Coccidioidomycosis is a disease caused by the fungi Coccidioides immitis and accompanied by the formation of inflammatory infiltrates of various sizes in the lungs, skin and bones. Infection occurs mainly through the respiratory organs, less often through the skin. Diagnosis is based on the identification of the pathogen by microscopic examination and seeding of the separated. Treatment consists in the use of modern antifungal drugs.
Coccidioidomycosis is common in steppe and desert areas, it is endemic, that is, tied to certain natural conditions, a disease. In Europe, disease occurs in isolated cases, whereas in some areas of the United States, various manifestations of this disease are observed in 60% of the population.
Coccidioidomycosis is a fungal disease. Its causative agent is the fungus Coccidioides immitis, the development of which occurs in the soil. With dust, the spores of the fungus are carried through the air and can enter the human body when inhaled. Infection is possible through damaged skin integuments or through the mucous membrane of the gastrointestinal tract when eating products infected with spores. Cases of human infection from sick people or animals have not been identified.
Disease develops 7-18 days after infection through the respiratory tract. When infected through the skin, this period increases to a month or more. In the majority of infected (about 60%), the primary infection has an asymptomatic course. In a quarter of those infected with coccidioidomycosis, respiratory organs are affected, which initially proceeds according to the type of ARI. Then cough, shortness of breath and chest pains are added. Small foci of inflammation appear in the lungs – granulomas, which can merge, sometimes affecting the whole lobe. The clinical picture corresponds to bronchitis or pneumonia, in some cases pleurisy develops.
The involvement of the skin in the infectious process occurs, as a rule, 1-2 weeks after the onset of pulmonary manifestations. When infected with coccidioidomycosis through the skin, skin manifestations occur without previous changes on the part of the respiratory organs. The skin of the extremities, head and neck is more often affected. The rash has the character of nodular erythema and is caused by the appearance of small inflammatory infiltrates in the skin. It is possible to form abscesses in the skin and the appearance of nodular ulcerative elements. After opening the skin infiltrates, ulcers remain, the bottom of which is covered with vegetations. Epithelizing, ulcers leave stellate scars. A rash with coccidioidomycosis can be accompanied by soreness and swelling of the joints.
Disease is dangerous for the development of a septic (generalized) form of the disease, in which infection through the blood vessels can spread to any organ with the formation of fungal granulomas in it. Granulomas are prone to purulent melting, so the generalized form of coccidioidomycosis is very severe with severe intoxication and can lead to death. The most dangerous is the spread of infection into the membranes and substance of the brain with the development of abscesses and purulent meningitis.
A few years or months after acute coccidioidomycosis, secondary coccidioidomycosis may occur, which is characterized by a severe progressive course with extensive lesions of the lung tissue, ribs and vertebrae, as well as with the formation of infiltrates in the abdominal cavity.
Diagnosis and treatment
The causative agent can be detected by microscopy of specially colored smears obtained from sputum, separated skin elements, punctate pleural or articular fluid. To confirm coccidioidomycosis and determine the sensitivity of the pathogen to antifungal drugs, seeding of the discharge or sputum is carried out. For the serological diagnosis of coccidioidomycosis, a compliment binding reaction with a specific antigen (RSC) is used. Tests are carried out with the application of coccidioidin to the skin. However, it should be borne in mind that skin tests are positive for several years after suffering coccidioidomycosis.
If coccidioidomycosis occurs with damage to the respiratory organs, then foci of pneumonia or abscesses are determined on lung radiographs. When symptoms of meningitis appear, a lumbar puncture is performed with subsequent examination of the cerebrospinal fluid. According to the indications, a joint puncture or pleural puncture is performed.
Depending on the form and severity of this disease, treatment is carried out by oral administration, intravenous or intramuscular administration of antifungal agents (amphotericin B), posaconazole or various fluconazole preparations.