CHAPTER 181
Fungal Infections
Because fungal spores are often present in the air or in the soil, fungal infections usually begin in the lungs or on the skin.
Fungal infections are rarely serious unless the immune system is weakened, usually by drugs or disorders.
Fungal infections usually progress slowly.
Antifungal drugs may be applied directly to the infected site or, if the infection is serious, taken by mouth or injected.
Fungi are neither plants nor animals. They were once thought to be plants but are now classified as their own kingdom. Some fungi, including yeasts such as Candida and molds such as aspergilli, can be seen only through a microscope. Others, including bread molds and mushrooms, can be seen with the naked eye. Fungi can grow in a round shape (as yeasts) or in long, thin threads (hyphae). Some fungi go through both forms during their life cycle.
Some fungi reproduce by spreading microscopic spores. These spores are often present in the air, where they can be inhaled or come into contact with the surfaces of the body, primarily the skin. Consequently, fungal infections usually begin in the lungs or on the skin. Of the wide variety of spores that land on the skin or are inhaled into the lungs, most do not cause infection. Except for some superficial skin infections, fungal infections are rarely passed from one person to another. Typically, if the immune system is normal, fungal infections do not spread to organs deep in the body.
Did You Know…
Fungi are their own kingdom—neither plants nor animals.
Certain types of fungi (such as Candida) are normally present on body surfaces or in the intestine. Although normally harmless, these fungi sometimes cause localized infections of the skin and nails (see page 1320), vagina (see page 1540), mouth (see pages 1320 and 1364), or sinuses (see box on page 1399). Fungi seldom cause serious harm, except in people who have a weakened immune system or who have foreign material, including medical devices (such as an intravenous catheter or an artificial joint or heart valve), in their body.
Sometimes the normal balances that keep fungi in check are upset and infections occur. For example, the bacteria normally present in the digestive tract and vagina limit the growth of certain fungi in those areas. When people take antibiotics, the helpful bacteria can be killed, allowing the fungi to grow unchecked. The resulting overgrowth of fungi can cause symptoms, which are usually mild. As the bacteria grow back, the balance is restored, and the problem usually resolves.
Some fungal infections—histoplasmosis, blastomycosis, coccidioidomycosis, and paracoccidioidomycosis—can be serious in otherwise healthy people. The fungi that cause these infections exist in the environment in various parts of the world. Therefore, some fungal infections are more common in certain geographic areas. For example, in the United States, coccidioidomycosis occurs almost exclusively in the Southwest. Histoplasmosis is especially common in the Ohio and Mississippi River valleys. Blastomycosis is particularly common in the eastern and central United States (and in Africa).
Because many fungal infections develop slowly, months or years may pass before people seek medical attention. But in people with a weakened immune system, fungal infections can be very aggressive, spreading quickly to other organs and often leading to death. The immune system may be weakened by taking drugs that suppress the immune system (immunosuppressants), such as chemotherapy drugs or drugs used to prevent rejection of an organ transplant, or by having a disorder, such as AIDS.
Several drugs effective against fungal infections are available, but the structure and chemical makeup of fungi make them difficult to kill. Anti-fungal drugs may be applied directly to a fungal infection of the skin or other surface, such as the vagina or inside of the mouth. Antifungal drugs may also be taken by mouth or injected when needed to treat more serious infections. For serious infections, several months of treatment are often needed.
Aspergillosis
Aspergillosis is infection, usually of the lungs, caused by the fungus Aspergillus.
A ball of fungus fibers, blood clots, and white blood cells may form in the lungs or sinuses.
People may have no symptoms or may cough up blood or have a fever, chest pain, and difficulty breathing.
If fungi spread to the liver or kidneys, these organs may malfunction.
Diagnosis usually involves an x-ray or computed tomography and, if possible, culture of a sample of infected material.
Antifungal drugs are used, and sometimes surgery is needed to remove the fungi.
Aspergilli are very common and frequently occur in compost heaps, air vents, and airborne dust. Inhalation of Aspergillus spores is the primary cause of aspergillosis. Aspergillosis has several forms:
Pulmonary aspergilloma: Aspergillosis usually develops in open spaces in the body, such as cavities in the lungs caused by preexisting lung disorders. The infection may also develop in the ear canals and sinuses. In the sinuses and lungs, aspergillosis develops as a ball (aspergilloma) composed of a tangled mass of fungus fibers, blood clots, and white blood cells. The ball gradually enlarges, destroying lung tissue in the process, but usually does not spread to other areas.
Invasive aspergillosis: Less often, aspergillosis becomes very aggressive and rapidly spreads throughout the lungs and often through the bloodstream to the brain, heart, liver, and kidneys. This rapid spread occurs mainly in people with a weakened immune system.
Allergic bronchopulmonary aspergillosis: Some people who have asthma or cystic fibrosis develop a chronic allergic reaction with cough, wheezing and fever if Aspergillus colonizes the lining of their airways (see page 516).
Symptoms
A fungus ball in the lungs may cause no symptoms and may be discovered only when a chest x-ray is taken for other reasons. Or it may cause repeated coughing up of blood and, rarely, severe, even fatal bleeding. A rapidly invasive infection in the lungs often causes cough, fever, chest pain, and difficulty breathing. Without treatment, this form of invasive aspergillosis is fatal.
Risk Factors for Developing Fungal Infections
USE OF DRUGS THAT SUPPRESS THE IMMUNE SYSTEM
Cancer chemotherapy drugs
Corticosteroids
Drugs to prevent rejection of an organ transplant, such as azathioprine, methotrexate, and cyclosporine
DISORDERS
AIDS
Burns, if extensive
Diabetes
Hodgkin lymphoma or other lymphomas
Kidney failure
Lung disorders, such as emphysema
Leukemia
Aspergillosis that spreads to other organs makes people very ill. Symptoms include fever, chills, shock, delirium, and blood clots. Kidney failure, liver failure (causing jaundice), and breathing difficulties may develop. Death can occur quickly.
Aspergillosis of the ear canal causes itching and occasionally pain. Fluid draining overnight from the ear may leave a stain on the pillow. Aspergillosis of the sinuses causes a feeling of congestion and sometimes pain or discharge.
Diagnosis
Doctors suspect the diagnosis based on symptoms. An x-ray or computed tomography (CT) of the infected area also provides clues for making the diagnosis.
Whenever possible, doctors send a sample of infected material to a laboratory to grow (culture), examine, and confirm identification of the fungus. A viewing tube (bronchoscope or rhinoscope) may be used to obtain this material from the lungs or sinuses.
Treatment
Aspergillosis that affects only a sinus or a single area in the lung requires treatment but does not pose an immediate danger because it progresses slowly. However, if the infection is widespread or if people appear seriously ill, treatment is started immediately.
Invasive aspergillosis is treated with antifungal drugs, such as amphotericin B or voriconazole. However, some forms of Aspergillus do not respond to these drugs and may need to be treated with caspofungin, a newer antifungal drug, with or without the other drugs.
Doctors treat aspergillosis in the ear canal by scraping out the fungus and applying drops of antifungal drugs. Collections of fungi in the sinuses must usually be removed surgically. If fungus balls in the lungs grow near large blood vessels, they may also need to be removed surgically because they may invade the blood vessel and cause bleeding.
Blastomycosis
Blastomycosis (North American blastomycosis, Gilchrist’s disease) is infection, mainly of the lungs, caused by the fungus Blastomyces dermatitidis.
DRUGS FOR SERIOUS FUNGAL INFECTIONS
| DRUG | COMMON USES | SOME SIDE EFFECTS |
| Amphotericin B | Wide variety of fungal infections | Chills, fever, headache, vomiting, lowered potassium levels in blood, kidney damage, and anemia |
| Anidulafungin Caspofungin Micafungin |
Aspergillus, candidal, and possibly other infections | Fever, nausea, and inflammation of veins |
| Fluconazole | Candidal and other fungal infections, including cryptococcal | Liver inflammation (hepatitis) but less than that with ketoconazole |
| Flucytosine | Candidal and cryptococcal infections | Bone marrow and kidney damage |
| Itraconazole | Candidal and other fungal infections | Nausea, diarrhea, and liver inflammation but less than that with ketoconazole Erratic absorption of the drug from the intestine |
| Ketoconazole | Candidal and other fungal infections | Nausea and vomiting, blocked production of testosterone and cortisol, and liver inflammation |
| Posaconazole | Aspergillus, candidal, and many other fungal infections | Nausea, vomiting, and rarely liver inflammation |
| Voriconazole | Aspergillus and candidal infections | Visual disturbances that are reversible |
People have a fever, chills, and drenching sweats and sometimes chest pain, difficulty breathing, and a cough.
The infection may spread to the skin, bones, reproductive and urinary tracts, and tissues covering the brain, causing swelling, pain, and other symptoms.
A sample of infected sputum or tissues is removed and sent for culture.
Antifungal drugs must be taken for months.
Spores of Blastomyces probably enter the body through the airways when the spores are inhaled. Thus, blastomycosis affects primarily the lungs, but the fungi occasionally spread through the bloodstream to other areas of the body, including the skin.
Most infections occur in the United States, chiefly in the Southeast and the Mississippi River valley, where the fungus lives in the soil near river beds. Infections have also occurred in widely scattered areas of Africa. Men aged 20 to 40 years are most commonly infected. Unlike most fungal infections, blastomycosis is not more common among people with AIDS.
Symptoms
Blastomycosis of the lungs begins gradually with a fever, chills, and drenching sweats. Chest pain, difficulty breathing, and a cough that may or may not bring up sputum may also develop. The lung infection usually progresses slowly, but people sometimes get better without treatment.
When blastomycosis spreads, it can affect many areas of the body, but the skin, bones, and reproductive and urinary tracts (including the prostate gland) are the most common sites. Skin infection begins as very small, raised bumps (papules), which may contain pus. Raised, warty patches then develop, surrounded by tiny, painless collections of pus (abscesses). Tissues over infected bones may become swollen and painful. In men, the coiled tube on top of testes (epididymis) may swell, causing pain, or infection of the prostate gland (prostatitis) may cause discomfort.
Occasionally, fungi spread to the tissues that cover the brain and spinal cord (meninges), causing fungal meningitis. This infection can cause headache and confusion.
Diagnosis and Treatment
A doctor diagnoses blastomycosis by sending a sample of sputum or infected tissue to a laboratory to be examined under a microscope and cultured.
Blastomycosis may be treated with amphotericin B, given intravenously, or itraconazole or voriconazole, given by mouth. With treatment, people begin to feel better fairly quickly, but the drug must be continued for months. Without treatment, blastomycosis slowly worsens and leads to death.
Candidiasis
Candidiasis (candidosis, moniliasis, yeast infection) is infection caused by several species of Candida, especially Candida albicans.
The most common type of candidiasis is a superficial infection of the mouth, vagina, or skin that causes white or red patches and itching, irritation, or both.
People whose immune system is weakened may have serious infections of the esophagus and other internal organs.
A sample of infected material is examined under a microscope and sent for culture.
Antifungal drugs may be applied to the surface or taken by mouth, but serious infections require drugs given by vein.
Candida is normally present on the skin, in the intestinal tract, and, in women, in the genital area. Usually, Candida in these areas does not cause problems. However, the fungi sometimes cause infection of the skin (see page 1320), the mucous membranes of the mouth (see pages 1320 and 1364), or vagina (see page 1540). Such infections can develop in people with a healthy immune system, but they are more common or persistent in people with diabetes, cancer, or AIDS and in pregnant women. Candidiasis is also common among people who are taking antibiotics because the antibiotics kill the bacteria that normally compete with Candida, allowing Candida to grow unchecked.
Some people, mainly those with a weakened immune system, develop candidiasis that spreads through the bloodstream (called candidemia) to other parts of the body, such as the heart valves, spleen, kidneys, and eyes. Without treatment, this infection progresses.
Symptoms
Infection of the mouth (thrush or trench mouth) causes the following:
Creamy, white, painful patches inside the mouth
Cracking at the corners of the mouth (cheilitis)
A red, painful, smooth tongue
Patches in the esophagus cause pain during swallowing.
When the skin is infected, a burning rash develops. Some types of diaper rash are caused by Candida.
If the infection spreads to other parts of the body, it is more serious. It can cause fever, a heart murmur, enlargement of the spleen, dangerously low blood pressure (shock), and decreased urine production. An infection of the retina and inner parts of the eye can cause blindness. If the infection is severe, several organs may stop functioning, and death can occur.
Diagnosis
Many candidal infections are apparent from the symptoms alone. To confirm the diagnosis, a doctor must identify the fungi in a sample viewed under a microscope. Samples of blood or other infected tissues may be sent to a laboratory to be cultured and examined to identify the fungi.
Treatment
Candidiasis that occurs only on the skin or in the mouth or vagina can be treated with antifungal drugs (such as clotrimazole and nystatin) that are applied directly to the affected area. A doctor may prescribe the antifungal drug fluconazole to be taken by mouth.
Candidiasis that has spread throughout the body is usually treated with amphotericin B given intravenously. Other antifungal drugs—fluconazole and related drugs (posaconazole and voriconazole) or caspofungin and related drugs (micafungin and anidulafungin)—are also effective.
Candidiasis is more serious and less responsive to treatment in people with certain disorders, such as diabetes. In people with diabetes, controlling blood sugar levels facilitates cure of the infection.
Coccidioidomycosis
Coccidioidomycosis (San Joaquin fever, valley fever) is infection, usually of the lungs, caused by the fungus Coccidioides immitis.
The infection is caused by inhaling spores of the fungus.
If mild, the lung infection causes flu-like symptoms and sometimes shortness of breath, but the infection may worsen and spread throughout the body, causing various symptoms.
The diagnosis can be confirmed by identifying the fungi in samples of infected materials examined under a microscope or cultured.
Antifungal drugs, given by mouth or intravenously, must be taken for years, sometimes for life.
The spores of Coccidioides are present in soil in the southwestern United States, Central America, and South America. Farmers and others who work with or are exposed to disturbed soil are most likely to inhale the spores and become infected. People who become infected while traveling may not develop symptoms until after they go home.
Coccidioidomycosis occurs in two forms:
Mild lung infection (acute primary coccidioidomycosis): The infection disappears without treatment. It accounts for about half of cases.
Severe, progressive infection (progressive coccidioidomycosis): The infection spreads throughout the body and is often fatal. It is more common among men and among blacks, Filipinos, and Native Americans. This form is more likely to occur when the immune system is weakened—by disorders (particularly AIDS) or by drugs that suppress the immune system (immunosuppressants).
Did You Know…
An allergic reaction to the Coccidioides fungus usually means that people are effectively fighting off the infection.
Symptoms
Most people with acute primary coccidioidomycosis have no symptoms. If symptoms develop, they appear 1 to 3 weeks after people are infected. Symptoms are usually mild and often flu-like. They include a cough, fever, chills, chest pain, and sometimes shortness of breath. The cough may produce sputum and occasionally blood. Some people develop desert rheumatism, which includes inflammation of the surface of the eye (conjunctivitis) and joints (arthritis) and formation of skin nodules (erythema nodosum). These effects, which can be painful, are allergic reactions to the fungus and usually imply that people are fighting off the fungus effectively.
The progressive form is uncommon and may develop weeks, months, or even years after the initial infection. Symptoms include mild fever and loss of appetite, weight, and strength. The lung infection may worsen, causing increased shortness of breath. The infection may also spread from the lungs to the bones, joints, liver, spleen, and kidneys. Joints may become swollen and painful. The fungi can also infect the brain and the tissues covering the brain (meninges), causing meningitis. This infection is often chronic, causing headaches, confusion, loss of balance, double vision, and other problems. Untreated meningitis is always fatal.
Diagnosis
A doctor may suspect coccidioidomycosis if people develop symptoms after living in or recently traveling through an area where the infection is common. Chest x-rays usually show abnormalities. But to identify the fungi and thus confirm the diagnosis, doctors may examine samples of blood, sputum, pus, or other infected tissue under a microscope or send them to a laboratory to be cultured.
Treatment
Acute primary coccidioidomycosis typically goes away without treatment, and recovery is usually complete. However, some doctors prefer to treat coccidioidomycosis if it affects the lungs.
For the progressive form, fluconazole is given by mouth, or amphotericin B is given intravenously. Alternatively, the doctor may treat the infection with voriconazole or posaconazole.
If meningitis develops, amphotericin B or fluconazole is given intravenously. In addition, amphotericin B may be injected directly into the spinal fluid.
Although drug treatment can be effective in localized infections (for example, in the skin, bones, or joints), relapses often occur after treatment is stopped. Treatment must therefore be continued for years, often for life.
Allergic symptoms often require treatment, such as corticosteroids.
Cryptococcosis
Cryptococcosis is infection caused by the fungus Cryptococcus neoformans.
People may have no symptoms or may have headache and confusion, a cough and an achy chest, or a rash, depending on where the infection is.
The diagnosis is based on culture and examination of tissue and fluid samples.
Antifungal drugs are given by mouth or, if the infection is severe, intravenously.
Cryptococcus occurs primarily in soil that is contaminated with pigeon droppings. The fungus is present around the world, but infection was relatively rare until the AIDS epidemic began. The fungus sometimes infects people with Hodgkin lymphoma or sarcoidosis and those who are receiving long-term corticosteroid treatment. However, cryptococcosis can also develop in people with a normal immune system.
Cryptococcosis occurs mainly in the following:
Tissues covering the brain and spinal cord (meninges), resulting in meningitis
Lungs
Skin
Other organs are sometimes involved.
Symptoms and Diagnosis
Cryptococcosis usually causes mild and vague symptoms. Other symptoms occur depending on where the infection is:
Meningitis: Headache and confusion
Lung infection: No symptoms in some people, a cough or an aching chest in others, and, if the infection is severe, difficulty breathing
Skin infection: A rash, consisting of bumps (sometimes filled with pus) or open sores
To diagnose the infection, a doctor takes samples of tissue and body fluids to be cultured and examined. Blood and spinal fluid may be tested for certain substances released by Cryptococcus.
Treatment
People with a functioning immune system who have Cryptococcus in only a small part of their lungs usually do not require any treatment. However, people with a lung infection are often treated with fluconazole, given by mouth, to shorten the duration of their illness. For meningitis, amphotericin B and flucytosine are given intravenously, followed by fluconazole given by mouth. For a skin infection, people are usually given fluconazole by mouth or, if the infection is severe, amphotericin B intravenously.
People with a weakened immune system may be given fluconazole, amphotericin B, sometimes flucytosine, or a combination. If people with AIDS develop cryptococcosis, they usually need to take an antifungal drug, usually fluconazole, for the rest of their life. However, they may be able to stop the antifungal drug if their CD4 count (the number of one type of white blood cell) increases and stays high enough for at least 6 months.
Histoplasmosis
Histoplasmosis is infection caused by the fungus Histoplasma capsulatum. It occurs mainly in the lungs but can sometimes spread throughout the body.
The infection is caused by inhaling spores of the fungus.
Most people do not have symptoms, but some feel sick and have a fever and cough, sometimes with difficulty breathing.
Sometimes the infection spreads, causing the liver, spleen and lymph nodes to enlarge and damaging other organs.
The diagnosis is based on culture and examination of tissue and fluid samples.
Whether treatment with antifungal drugs is needed depends on the severity of the infection.
The spores of Histoplasma are present in the soil and are particularly common in the eastern and Midwestern United States, along the Ohio and Mississippi river valleys. Farmers and others who work with soil are most likely to inhale the spores. Severe infection can result when large numbers of spores are inhaled. People with human immunodeficiency virus (HIV) infection are more likely to develop histoplasmosis, especially the form that spreads through the bloodstream to other parts of the body, such as the liver, spleen, lymph nodes, adrenal glands, digestive system, and bone marrow.
Symptoms
Most people with histoplasmosis do not develop any symptoms. However, the following three forms cause symptoms, as do some rare forms.
Acute Pulmonary Histoplasmosis: Symptoms usually appear 3 to 21 days after people inhale the spores. People may feel sick, have a fever and a cough, and feel as though they have the flu. Symptoms usually disappear without treatment in 2 weeks and rarely last longer than 6 weeks.
This form is very rarely fatal but can become serious in people with a weakened immune system (such as those with AIDS).
Progressive Disseminated Histoplasmosis: This form does not normally affect healthy adults. It usually occurs in infants or very young children and in people with a weakened immune system. Symptoms are vague at first. People may experience fatigue, weakness, and a general feeling of illness (malaise). Symptoms may worsen very slowly or extremely rapidly. The liver, spleen, and lymph nodes may enlarge. Less commonly, the infection causes ulcers to form in the mouth and intestines. Rarely, the adrenal glands are damaged, causing Addison’s disease (see page 999).
Without treatment, this form is fatal in 90% of people. Even with treatment, death may occur rapidly in people with AIDS.
Chronic Cavitary Histoplasmosis: This lung infection develops gradually over several weeks, causing a cough and increased difficulty breathing. Symptoms include weight loss, a mild fever, and a general feeling of illness (malaise).
Most people recover without treatment within 2 to 6 months. However, breathing difficulties may gradually worsen, and some people cough up blood, sometimes in large amounts. Lung tissue is destroyed, and scar tissue forms. Lung damage or bacterial invasion of the lungs may eventually cause death.
Diagnosis
To make the diagnosis, a doctor obtains samples of the sputum, bone marrow, urine, or blood. Samples may also be taken from the liver, lymph nodes, or any mouth ulcers that are present. These samples are sent to a laboratory for culture and examination. Urine and blood may be tested for proteins (antigens) released by the fungus.
For some rare forms of the infection, the help of infectious disease specialists is required for diagnosis (and treatment).
Treatment
People with acute pulmonary histoplasmosis rarely require drug treatment. However, fluconazole or itraconazole is often prescribed to shorten the duration of the illness.
People with progressive disseminated histoplasmosis need treatment and often respond well to amphotericin B given intravenously or to itraconazole (or other related drugs) given by mouth. If people with AIDS develop histoplasmosis, they may need to take an antifungal drug, usually itraconazole, for the rest of their life. However, they may be able to stop the antifungal drug treatment if their CD4 count (the number of one type of white blood cell) increases and stays high enough for at least 6 months.
In chronic cavitary histoplasmosis, itraconazole or, for more serious infections, amphotericin B may eliminate the fungus. However, treatment cannot reverse the destruction caused by the infection. Thus, most people continue to have breathing problems, similar to those caused by chronic obstructive pulmonary disease. Therefore, treatment should begin as soon as possible to limit lung damage.
Mucormycosis
Mucormycosis (zygomycosis) is infection caused by Mucorales molds.
The infection is caused by inhaling spores produced by the mold.
The infection causes pain, fever, and sometimes cough and can destroy structures in the face.
Doctors diagnose the infection by identifying the fungus in tissue samples.
Most people are given high doses of amphotericin B intravenously, and surgery is done to remove infected and dead tissue.
Mucormycosis is caused by inhaling spores produced by Mucorales molds. These molds are common in the environment and include many common bread molds. People probably breathe in the spores of these molds all the time. However, most of these molds do not cause infection.
This infection most commonly affects the nose, sinuses, eyes, and brain—a form called rhinocerebral mucormycosis. This severe and potentially fatal infection typically affects people whose immune system is weakened by a disorder, such as undernutrition or uncontrolled diabetes. The other common site of infection is the lungs. Rarely, the skin and digestive system are infected.
Symptoms
Symptoms of rhinocerebral mucormycosis include pain, fever, and infection of the eye socket (orbital cellulitis) with bulging of the affected eye (proptosis). Pus is discharged from the nose. The roof of the mouth (palate), the facial bones surrounding the eye socket or sinuses, or the divider between the nostrils (septum) may be destroyed by the infection. Infection in the brain may cause seizures, partial paralysis, and coma.
Mucormycosis in the lungs causes fever, cough, and sometimes difficulty breathing.
The fungus tends to invade arteries. As a result, blood clots form and tissue dies. The fungus grows uncontrolled in the dead tissue, which becomes black. The surrounding area may bleed.
Diagnosis
Because symptoms of mucormycosis can resemble those of other infections, a doctor may not be able to diagnose it immediately. Usually, the diagnosis is made when a doctor identifies the fungus in cultures of samples of infected tissue.
Did You Know…
Without early diagnosis and treatment, mucormycosis can damage the face so badly that the required surgery results in disfigurement.
Treatment
Most people with mucormycosis are treated with high doses of amphotericin B given intravenously. People with uncontrolled diabetes are given insulin to lower blood sugar levels.
Infected tissue and especially dead tissue must be removed by surgery. Early diagnosis and treatment of this infection are important to avoid death or extensive surgery, which often causes disfigurement.
Mucormycosis is very serious. Even when as much infected and dead tissue as possible is removed and antifungal drugs are used appropriately, many people with this infection die.
Paracoccidioidomycosis
Paracoccidioidomycosis (South American blastomycosis) is infection caused by the fungus Paracoccidioides brasiliensis.
Paracoccidioidomycosis usually involves the skin, mouth, throat, and lymph nodes, although it sometimes appears in the lungs, liver, or spleen. It is very common in South and Central America but rare in the United States. It infects people after they inhale the spores, which grow in the soil. Men aged 20 to 50 are typically affected.
Symptoms
Infected lymph nodes become swollen and may drain pus, but there is little pain. The lymph nodes most commonly infected are those in the neck and under the arms. Painful ulcers may form in the mouth. If the lungs are affected, people may have a cough and difficulty breathing. The liver and spleen may enlarge. Symptoms last a long time but are rarely fatal.
Diagnosis and Treatment
To diagnose the infection, a doctor takes tissue samples for examination under a microscope and for culture.
The antifungal drug itraconazole is the treatment of choice. Amphotericin B is also effective, but because of its side effects, it is reserved for very severe cases.
Sporotrichosis
Sporotrichosis is infection caused by the fungus Sporothrix schenckii.
The infection develops when the fungi enter the body through a puncture wound.
Usually, the skin and lymph nodes are infected, resulting in bumps on the skin and swollen lymph nodes.
Rarely, the lungs, joints, or other parts of the body are infected.
Diagnosis requires culture and identification of the fungus in a sample of infected tissue.
Itraconazole is used to treat most infections, but amphotericin B is required for bodywide infections.
Sporothrix fungi typically grow on rosebushes, barberry bushes, sphagnum moss, and other mulches. In contrast to many other fungal infections, Sporothrix fungi enter the body through a puncture wound to the skin. Most often, farmers, gardeners, and horticulturists are infected.
Sporotrichosis affects mainly the skin and nearby lymphatic vessels. Very rarely, bones, joints, lungs, or other tissues are infected.
Symptoms and Diagnosis
An infection of the skin typically starts on a finger as a small, nontender bump (nodule) that slowly enlarges and forms a sore. Over the next several days or weeks, the infection spreads through the lymphatic vessels of the finger, hand, and arm to the lymph nodes, forming nodules and sores along the way. Even at this stage, there is little or no pain. Usually, people have no other symptoms. This infection is seldom fatal.
An infection in the lungs may cause pneumonia, with a slight chest pain and cough. Lung infection usually occurs in people who have another lung disorder, such as emphysema. Joint infection causes swelling and makes movement painful. Rarely, an infection develops in other areas and can spread throughout the body. Such infections are life threatening.
The characteristic nodules and sores may lead a doctor to suspect sporotrichosis. The diagnosis is confirmed by growing (culturing) and identifying Sporothrix in samples of infected tissue.
Treatment
Skin infections are treated with itraconazole given by mouth. Potassium iodide, given by mouth, may be prescribed instead, but it is not as effective and, in most people, has side effects (such as a rash, a runny nose, and inflammation of the eyes, mouth, and throat).
Lung and bone infections may also be treated with itraconazole. For bodywide infections, amphotericin B is given intravenously.