Tinea Corporis and Tinea Pedis Can Masquerade As Other Cutaneous Conditions in Decedents: Forensic Dermatology of Dermatophyte Infections.

Decedents can have lesions of their skin, mucosa, hair, or nails that may be related to their cause of death; alternatively, these lesions may be coincidentally present and not have associated forensic implications. Superficial fungal infection of the skin, such as tinea corporis and tinea pedis, can mimic other cutaneous conditions, including diseases, neoplasms, or infection. Two decedents had superficial fungal infections that mimicked other conditions, and the cutaneous presentation of their dermatophyte infection was selected to be reported based on their illustrative value. Dermatophyte infections of the body can present with extensive involvement of the skin; a decedent had diffuse tinea corporis that clinically mimicked psoriasis vulgaris, dermatitis, and cutaneous T-cell lymphoma; the diagnosis of a fungal infection of the skin was established after microscopic examination of lesional skin biopsies. The fungal organisms could not be readily visualized on the hematoxylin and eosin-stained sections; however, the fungal hyphae were easily observed after the sections were stained with periodic acid-Schiff stain. Another decedent had two different acquired skin conditions; the first appeared as cutaneous plaques; the differential diagnosis included ichthyosis, dermatitis, and tinea corporis. Examination of the epidermis from a skin biopsy showed the absence of both the granular layer and fungal hyphae on hematoxylin and eosin-stained sections, and the periodic acid-Schiff stain did not demonstrate any fungal organisms; this confirmed the suspected diagnosis of acquired ichthyosis. The second skin disease appeared as severe hyperkeratosis of the soles; the plantar lesions prompted the consideration of secondary syphilis plantar lesions; serologic evaluation was negative for spirochetal infection, and the periodic acid-Schiff-stained sections of the plantar skin biopsy showed fungal hyphae, establishing the diagnosis of hyperkeratotic (moccasin-type) tinea pedis. In summary, a cutaneous dermatophyte infection can morphologically present like a skin condition, a cutaneous malignancy, or an infection with mucocutaneous symptoms. In addition, more than one skin condition may be concurrently present in a decedent. Therefore, in conclusion, the forensic pathologist should entertained the possibility of performing a skin biopsy of any papulosquamous skin lesion on a decedent; importantly, the microscopic evaluation of the tissue section should not only be stained with hematoxylin and eosin but also with a stain which readily allows superficial fungal hyphae to be observed in the stratum corneum of the epidermis such as periodic acid-Schiff stain.