Photo Rounds

Itchy pustules over hair follicles

A 48-year-old man with a history of psoriasis and psoriatic arthritis presented for follow-up. The patient had been taking adalimumab (Humira) 40 mg every other week for 2 years, and his skin was largely clear of psoriasis except for one very itchy area on his left forearm that had been bothering him for about 3 months. The primary lesion was a pustule and it was surrounded by multiple pustules that were located over hair follicles and formed an annular plaque.

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References

Itchy pustules over hair follicles

A potassium hydroxide (KOH) preparation of pus and dry superficial skin taken from 1 of the pustules revealed multiple hyphae and confirmed a diagnosis of nodular granulomatous perifolliculitis, also called Majocchi granuloma.

Majocchi granuloma is a reactive process of inflammation caused by infection of the follicular unit(s) by a dermatophyte—most often the same Trichophyton species responsible for more superficial tinea. On exam, there may be a solitary papule, pustule, or nodule. More often, there are multiple papules and pustules grouped within an annular plaque in hair-bearing areas on the head, trunk, or extremities. Majocchi granuloma can occur in patients who are healthy and those who are immunosuppressed.1 It can also occur when a topical steroid is applied to unsuspected tinea, as occurred here. In this case, the patient was accustomed to having multiple skin plaques of psoriasis and assumed this was a stubborn manifestation of that.

Because the infection penetrates deeper than most topical therapies can effectively reach at adequate concentrations, systemic medications are the treatments of choice. Terbinafine, itraconazole, and fluconazole are all effective options but need to be used for several weeks to be effective.

This patient received terbinafine 250 mg/d for 6 weeks and the pustules cleared completely. He continued with his other psoriasis medications throughout his treatment.

Photos and text for Photo Rounds Friday courtesy of Jonathan Karnes, MD (copyright retained). Dr. Karnes is the medical director of MDFMR Dermatology Services, Augusta, ME.

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