Alternariosis

A fungal infection caused by Alternaria species

Alternariosis is a fungal infection caused by species of the genus Alternaria. These fungi are commonly found in the environment and can affect both plants and humans. In humans, alternariosis is considered an opportunistic infection, primarily affecting individuals with compromised immune systems.

Pathophysiology

Alternaria species are saprophytic fungi that thrive in decaying organic matter. They are ubiquitous in nature and can be found in soil, air, and on plants. In humans, infection occurs when the spores of Alternaria are inhaled or come into contact with the skin. The fungi can cause a range of symptoms depending on the site of infection.

Clinical Manifestations

Cutaneous Alternariosis

Cutaneous lesions caused by Alternaria species.

Cutaneous alternariosis is the most common form of the infection. It typically presents as chronic, non-healing skin lesions that may appear as nodules, plaques, or ulcers. These lesions are often found on exposed areas of the body, such as the hands and face.

Respiratory Alternariosis

Inhalation of Alternaria spores can lead to respiratory symptoms, particularly in individuals with asthma or chronic obstructive pulmonary disease (COPD). Symptoms may include coughing, wheezing, and shortness of breath. In severe cases, it can lead to allergic bronchopulmonary mycosis.

Systemic Alternariosis

Systemic infection is rare and usually occurs in immunocompromised patients, such as those with HIV/AIDS, cancer, or those undergoing immunosuppressive therapy. It can lead to widespread dissemination of the fungus, affecting multiple organs and systems.

Diagnosis

Diagnosis of alternariosis is based on clinical presentation, histopathological examination, and culture of the organism from clinical specimens. Direct microscopy and culture can help identify the characteristic conidia of Alternaria species. Molecular techniques, such as polymerase chain reaction (PCR), may also be used for definitive identification.

Treatment

Treatment of alternariosis involves the use of antifungal medications. The choice of antifungal agent depends on the severity and location of the infection. Commonly used antifungals include itraconazole, voriconazole, and amphotericin B. In cases of cutaneous infection, surgical excision of the lesions may be necessary.

Prevention

Preventive measures include minimizing exposure to Alternaria spores, especially for individuals with weakened immune systems. This can be achieved by maintaining good indoor air quality, using air filtration systems, and avoiding activities that disturb soil or decaying plant matter.

Related pages

• Fungal infection
• Opportunistic infection
• Immunocompromised host