Mycoses
Mycoses, or fungal infections, are caused by molds, which are types of filamentous fungi. These infections can affect various body systems, including the skin, hair, nails, and respiratory system. While thousands of mold species exist, most do not pose a risk to healthy individuals, as the body's immune system can typically fend off these fungi. However, individuals with weakened immune systems, such as those with HIV/AIDS, or those with chronic lung conditions, are at a higher risk for developing serious mycoses. Common symptoms vary depending on the type of mold and the site of infection, ranging from superficial skin issues to severe respiratory symptoms. Diagnosis often involves clinical examinations, laboratory cultures, and imaging studies. Treatment options vary; superficial infections may not require treatment, while more serious mycoses may be addressed with antifungal medications. Given that fungi are ubiquitous in the environment, complete prevention of mold infections is often not feasible.
Mycoses
- ANATOMY OR SYSTEM AFFECTED: Hair, lungs, nails, respiratory system, scalp, skin
- ALSO KNOWN AS: Fungal infections
Definition
Mycoses (singular “mycosis”) are infections caused by molds (filamentous fungi).
Causes
Mycoses are caused by filamentous fungi or molds. There are thousands of species of molds, but most do not cause disease in healthy people. Molds are acquired from an environmental source and not through person-to-person contact. The most serious mycoses, such as aspergillosis, caused by Aspergillus sp., and coccidioidomycosis, caused by Coccidioides, begin in the lungs and may invade other tissues.
Risk Factors
Healthy people generally can combat the fungi they encounter. Deficiencies in the immune system, such as human immunodeficiency virus (HIV) infection, acquired immunodeficiency syndrome (AIDS), and neutropenia, and deficiencies caused by immunosuppressive therapy and even natural aging substantially increase the risk of mycoses. Other risk factors include poor lung function from other conditions such as chronic obstructive pulmonary disease, bronchiectasis, tuberculosis, sarcoidosis, and asthma.
Molds thrive in soil and moist environments. People who have prolonged exposure to soil, dust, and dirt are at greater risk of developing mold infections. Also, environments with poor ventilation can allow mold growth and spore formation, resulting in a higher risk of mold infections.
Symptoms
The symptoms of mycoses depend on the mold causing the infection and on the body site of the infection. Mycoses can be superficial-cutaneous or respiratory-systemic. Many mycoses are confined to the skin, hair, and nails. These superficial infections rarely penetrate or become a serious health concern, although with injury to the skin, they can become subcutaneous. Infection of the toenails or fingernails is called onychomycosis. More serious are respiratory mycoses, which can often spread to other organs and sites. Symptoms of respiratory mold infections are often nonspecific and can include fever, cough, headache, rash, muscle aches, night sweats, and hemoptysis.
Screening and Diagnosis
The diagnosis of fungal infections generally involves an examination or clinical observation to check for particular symptoms. Also, diagnosis may include a laboratory fungal culture from affected body sites, histologic examination of clinical material, serological tests for antibodies to specific fungi, and radiologic imaging. Definitive diagnosis usually requires laboratory culture of the fungus and identification based on morphological characteristics.
Treatment and Therapy
In many cases, no treatment is required for superficial or cutaneous mycoses. If the onychomycosis is serious, topical and oral therapies are available. Topical agents include amorolfine, ciclopirox olamine, and bifonazole/urea. Newer antifungal agents, such as itraconazole (Sporanox), fluconazole (Diflucan), and terbinafine (Lamisil and Terbinex), have been used to treat onychomycosis.
For systemic or otherwise more serious mycoses, the most effective antifungal for many years was amphotericin B. Liposomal formulations of amphotericin B have been developed with significantly less toxicity, but they remain effective against many invasive fungi.
New drugs in the azole class, such as itraconazole, voriconazole, ravuconazole, and posaconazole, are often used. An entirely new class of antifungals, the echinocandins, has also been developed.
Prevention and Outcomes
Most mold infections are very difficult, if not impossible, to prevent. Fungi are present in all environments. Generally, mold infections begin with airborne spores, which makes it impossible to avoid infection.
Bibliography
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