Majocchi granuloma (nodular granulomatous perifolliculitis) is a perifollicular and nodular process caused by infection of the follicle with a dermatophyte fungal species. The disease process occurs when a dermatophyte invades the follicle, causing a granulomatous and/or suppurative reaction in the dermis and/or subcutaneous tissue. Majocchi granuloma is most often caused by Trichophyton rubrum and less commonly by Trichophyton mentagrophytes or Epidermophyton floccosum. These are the same fungal species typically responsible for the superficial dermatophyte infections tinea corporis and tinea pedis. Other dermatophyte species have been implicated as well.

Majocchi granuloma can occur following trauma to the skin or from occlusion of hair follicles. This could be from shaving on the legs as well as the face. Involvement of the buttocks and genital skin has also been reported. The use of topical steroids on unsuspected tinea and immunosuppressed states can also predispose to its development. In children, infection could occur through animal contact.

While Majocchi granuloma is most common in young adults, it can be seen in children as well. It is also common in females who frequently shave their legs and in those with tinea pedis or onychomycosis.

A deeper and more nodular form of Majocchi granuloma has also been reported in transplant patients and immunocompromised patients. Human immunodeficiency virus (HIV)-infected individuals with tinea pedis may have a higher risk of progression to Majocchi granuloma on the feet and lower legs.

Majocchi-like granulomas, deep ulcerated fungal infections, severe tinea capitis and corporis, and fungal nail involvement are characteristic of an inherited deficiency of CARD9 (caspase recruitment domain-containing protein 9), an inflammatory cascade-associated protein. The disorder is autosomal recessive and is most common in North African countries including Algeria, Morocco, and Tunisia. The infections usually begin in childhood and are caused by T. rubrum and Trichophyton violaceum. Lymphadenopathy, high IgE antibody levels, and eosinophilia are common, and the disorder can be fatal.