Possible interaction between eosinophils and other immune cells in the pathomechanism of eosinophilic pustular folliculitis

A Case of Eosinophilic Pustular Folliculitis Misdiagnosed as Eczema

Eosinophilic pustular folliculitis (EPF) is a rare skin disease. The typical skin lesions of classic EPF are localized on the upper limbs' face, trunk, and extensor surfaces. However, when the skin lesions initially appear on the palms and soles, it is not easy to diagnose as EPF. Here, we report a case of a male patient who presented with erythematous plaques, pustules, and crusted erosions on the hands and feet, which were misdiagnosed as eczema ten years ago. Over ten years, the patient experienced recurrent erythematous patches with bumps and itching on the face, trunk, and extremities after improving the hand and foot lesions. A histopathological biopsy was performed to establish a definitive diagnosis, revealing pustules formed by eosinophilic infiltrates within the hair follicles. The diagnosis was confirmed as eosinophilic pustular folliculitis. The patient was treated with oral indomethacin at a dosage of 75mg/day, resulting in the disappearance of the skin lesions. After a 3-month follow-up, no recurrence was observed.

Clinical and Pathological Analysis of 10 Cases of Eosinophilic Pustular Folliculitis

We conducted a retrospective analysis of clinical and pathologic data from January 2020 to June 2023, focusing on 10 patients diagnosed with eosinophilic pustular folliculitis at our dermatology clinic. Four of the ten patients had the first rash on the face, five on the trunk, and one on the palms and feet, all of which were initially scattered papules that gradually increased and fused into erythematous plaques with a circular distribution. Seven had pustules with small surface desquamation, and three cases had micro swelling on the face. The rash involved only the face in 5 cases, the face and trunk in 5 cases, and the face, trunk, hands, and feet in 1 case. Seven of the ten patients were pruritic, and 3 had no obvious pruritus. The histopathological features were mild epidermal hyperplasia, lymphocytic and eosinophilic infiltration around the superficial middle dermal vessels and appendages, and eosinophilic and neutrophilic abscesses in the local hair follicles. Treatment with oral indomethacin, prednisone, and minocycline was effective.