Primary Cutaneous Cryptococcosis Mimicking Vasculitis in a Patient with Rheumatoid Arthritis.

Area of Science:

• Mycology
• Dermatology
• Immunocompromised Host Infections

Background:

• Cryptococcus spp. are known opportunistic pathogens, primarily in HIV-infected individuals.
• Recent trends show an increasing incidence of cryptococcosis in other immunocompromised patient groups.
• Long-term corticosteroid use for rheumatoid arthritis (RA) can predispose patients to opportunistic infections.

Purpose of the Study:

• To report a rare case of primary cutaneous cryptococcosis.
• To emphasize the diagnostic challenges and clinical presentation in an immunocompromised patient without HIV.
• To highlight the importance of considering fungal infections in non-healing skin lesions.

Main Methods:

• Clinical case presentation of a 73-year-old male with rheumatoid arthritis on long-term corticosteroids.
• Histopathological examination of skin biopsy with Periodic Acid-Schiff (PAS) and mucicarmine staining.
• Serological cryptococcal antigen testing.

Main Results:

• The patient presented with painful, non-healing ulceronecrotic lesions and hemorrhagic bullae.
• Skin biopsy revealed yeast forms consistent with Cryptococcus, confirmed by PAS and mucicarmine stains.
• Positive serum cryptococcal antigen test.
• Partial improvement in clinical symptoms with fluconazole treatment.

Conclusions:

• Primary cutaneous cryptococcosis is a rare but serious opportunistic infection in immunocompromised patients, including those with RA on corticosteroids.
• Cutaneous fungal infections should be considered in the differential diagnosis of non-healing skin lesions in immunocompromised individuals.
• Despite treatment, the patient succumbed to complications of his underlying systemic disease, underscoring the severity of opportunistic infections in this population.