December 2004

Fig.4

Fig5.

Histopathology:
Hematoxylin and eosin staining revealed alternating orthokeratosis and parakeratosis, acanthosis, and intracorneal neutrophils. A superficial and deep perivascular and periadnexal infiltrate of lymphocytes and eosinophils, extending into the subcutaneous tissue, was seen (Figure 4). No fungal organisms were identified by GMS stains.

Tissue and wound cultures taken from the abdomen and the left face revealed the diagnosis (Figure 5).

Diagnosis: Tinea barbae secondary to Trichophytin mentagrophytes

Discussion: Mycologic culture results were consistent with Trichophyton mentagrophytes. The culture plate growth is fluffy and white-buff colored. The back of the culture plate in this case is also buff colored, although this finding can vary from buff to a dark red. Round microconidia developing laterally and in clusters confirm the diagnosis, although this may take up to 2 weeks.

T. mentagrophytes var. mentagrophytes is a zoophilic dermatophyte, transmitted to humans by contact with cats, dogs, cattle, rodents, pigs, horses, and monkeys. In this case, transmission likely occurred via contact with an infected kitten. In addition, while our patient is a young, healthy male, his ability to mount an immune response to the invading dermatophyte may have been hindered by his use of high potency topical steroids to the affected area.

Dermatophytic infection localized to the bearded area of the face is classified as tinea barbae. Tinea barbae is by definition only found in post-pubertal males and is most often caused by T. mentagrophytes and T. verrucosum. In this case, the lesions were deep and nodular, with a purulent exudate, analogous to kerion-like lesions of the scalp. As in most cases, his lesions were confined to one side of the face.

Deep, pustular plaques affecting the hair-bearing skin of the body, also known as Majocchi's granuloma, are most commonly caused by T. mentagrophytes and T. rubrum. Such lesions may be seen in occluded areas, or in areas subject to trauma.

Finally, the descriptor "tinea incognito" is used in cases such as this, where a dermatophytic infection has been altered by the use of glucocorticoid treatment. In such cases, lesions appear atypical either because of lack of inflammation or because infection has evolved into a deep nodule or kerion.

Because both tinea barbae and Majocchi's granuloma involve invasion of the hair shaft, both are best treated with systemic antifungal treatments such as griseofulvin, terbinifine, itraconazole, and fluconazole. Because the patient was scheduled for immediate deployment, he was given a prescription for sporonox 150 mg daily for three weeks. He was continued on a topical antifungal cream as well as a low-potency topical steroid. He has not been seen in follow-up since his deployment.

References:

1. Martin AG, Kobayashi GS. Superficial Fungal Infection: Dermatophytosis, Tinea Nigra, Piedra. In: Freedberg IM, Eisen AZ, Wolff K, Austen KF, Goldsmith LA, Katz SI et al., editors. Fitzpatrick's Dermatology in General Medicine. New York, NY: McGraw-Hill, 1999: 2337-2357.

2. Sommer S, Barton RC, Wilkinson SM, Merchant WJ, Evans EG, Moore MK. Microbiological and molecular diagnosis of deep localized cutaneous infection with Trichophyton mentagrophytes. Br J Dermatol 1999; 141(2):323-325.