Primary Cutaneous Cryptococcosis in an Immunocompetent Patient: Diagnostic Workflow and Choice of Treatment

Cryptococcosis is an opportunistic infection in immunocompromised patients, involving mainly the lungs and central nervous system; however, the skin, eyes and genitourinary tract could also be involved as secondary sites of infection. Primary cutaneous cryptococcosis (PCC) is a distinct clinical entity that can occur in both immunocompetent and -compromised patients, usually trough skin injury. In immunocompetent patients, it is a very rare infection, presenting with non-specific clinical pictures and being challenging to diagnose. Herein, we present the case of an immunocompetent man with PCC due to Cryptococcus neoformans on his right forearm. PCC was diagnosed by a histological and cultural examination. Causes of concomitant immunosuppression were ruled out. A secondary cutaneous cryptococcosis was excluded with careful investigations. Therapy with oral fluconazole for three months was successfully performed, without evidence of recurrence in the following six months. Complete clinical recovery was achieved after three months of oral antifungal therapy, suggesting that longer courses of treatment could be avoided when faced with PCC in immunocompetent patients.

Mediastinal Small Cell Carcinoma with Primary Cutaneous Cryptococcosis: A Rare Case Report

Cutaneous cryptococcosis, an infectious disease resulting from Cryptococcus neoformans, primarily affects immunodeficient individuals. Here, we report a case of mediastinal small cell carcinoma (MSCC) complicated with multiple skin and soft tissue infections mimicking erysipelas and cellulitis. Antibiotics for bacteria were ineffective and a culture of pus from the infected areas revealed Cryptococcus neoformans in this patient. The absence of any evidence indicative of systemic cryptococcal infection leads to a final diagnosis of primary cutaneous cryptococcosis (PCC). Following two weeks of fluconazole at 400 mg/day and 200 mg/day for the subsequent three months, combined with incision, irrigation and drainage, the wound gradually healed. An analysis and discussion of the clinical features of this patient are presented. This case alerts clinicians as to the possibility of Cryptococcus neoformans in patients with advanced malignant tumors complicated with multiple skin and soft tissue infections. While a timely diagnosis and treatment of PCC in this patient resulted in a favorable outcome, the patient succumbed to the malignant tumor at six months post-discharge.

Primary Cutaneous Cryptococcosis in a Patient on Fingolimod: A Case Report

Primary cutaneous cryptococcosis is an uncommon condition. Patients with immunosuppression and those of older age are more susceptible to infection, warranting investigations into underlying systemic disease. We report the case of a 49-year-old male with multiple sclerosis in remission on fingolimod who presented with a non-healing skin lesion on his upper thigh for a duration of two years. Skin biopsy showed dermal parasitized histiocytes, and serum antigens for histoplasmosis and Cryptococcus were negative. Further investigation with polymerase chain reaction (PCR) demonstrated cutaneous cryptococcal infection, with no associated systemic signs or symptoms. This case report highlights an uncommon presentation of cutaneous cryptococcosis on an unexposed skin surface with successful and rapid improvement following fluconazole therapy without fingolimod discontinuation.

Cutaneous Cryptococcosis

Cutaneous cryptococcosis is classified either as primary or secondary based on the route of infection. The disease can also be classified either as localized cutaneous cryptococcosis or cutaneous manifestations of disseminated cryptococcosis. However, from a physician's point of view, whether lesions are localized to the skin or are disseminated/systemic is more important than the route of infection. The Clinical Practice Guidelines for Diagnosis and Treatment of Cryptococcosis, which was established in 2019 by the Japanese Society for Medical Mycology, adopted the latter classification. Localized cutaneous cryptococcosis is defined as a condition in which lesions are confined within a limited part of the skin, not systemically disseminated at the same time, and are associated with neither cryptococcal fungemia nor antigenemia. This type of cutaneous cryptococcosis is uncommon in Japan. Only 65 cases were reported during the 50-year study period from 1968 to August 2018, with the patients divided into two groups: immunocompromised patients (n=44, 68%) and immunocompetent patients (n=21, 32%). None of the patients were infected with the human immunodeficiency virus (HIV). Localized cutaneous cryptococcosis can also occur in non-HIV-infected patients and well-appearing individuals, therefore, it is considered an important infection in routine dermatology practice. Here, we outline the classification, diagnosis, and treatment of cutaneous cryptococcosis and present a summary of cutaneous cryptococcosis cases reported in Japan.