LAUSR

Dear Editor, A case of follicular mucinosis (FM) after herpes zoster infection (VZV), which can be considered an epithelial reaction pattern defined by follicular mucin accumulation due to different triggers, is presented. A 59-year-old woman, with no personal history of interest, attended to our outpatient dermatological clinic complaining pruritic lesions on the neck and left supraclavicular area for 2 months. A 3 months before, the patient had had a VZV in that location (Figure 1A), persisting postherpetic neuralgia. Physical examination revealed monomorphic erythematous papules confluent in plaques, distributed over the area of left C3–C5 dermatomes (Figure 1B,C). Laboratory test including blood count cell test, general biochemistry, and autoimmune analysis (autoantibodies, immunoglobulins and complement) were within normal limits. Histological findings showed perifollicular dermatitis with T CD4+ lymphocytes, CD123+ plasmacytoid dendritic cells and many dermal and perifollicular mucin (Figure 2A,B). No atypia or T/B clonality were observed. A diagnosis of FM was then established. The patient was treated with multiple ineffective treatments hydroxychloroquine 400 mg per day, prednisone 0.5 mg/kg/day and methotrexate 7.5 mg weekly 6 months, followed by minocycline 100 mg/day 2 months, and subsequently, narrowband Ultraviolet-B (nb-UVB) phototherapy for 3 months (starting dose of 0, 15 J/cm, increasing 20% of the previous dose every treatment, reaching a cumulative dose of 28, 66 J/cm). Finally, we started treatment with low-dose Ultraviolet-A1 (UVA1) phototherapy (UVA320L lamp, Waldmann), with an initial dose of 5 J/cm with 10% increases up to a maximum dose of 20 J/cm in a 3 sessions/ week regimen until reaching a cumulative dose of 334.75 J. Evaluation after 15 sessions showed partial clinical improvement with complete resolution at the end of treatment (30 sessions) (Figure 1D). No adverse effects were observed. Follicular mucinosis (FM) usually affects the head and neck as infiltrated erythematous plaques with follicular predominance, acneiform eruption and focal hair loss. The most accepted classification describes two variants: primary benign idiopathic FM and secondary FM, especially related to lymphomas as mycosis fungoides. It is also related to drugs, inflammatory dermatoses and infections. Kim MB, reported a case of FM secondary to VVZ as an isotopic Wolf phenomenon, clinically similar to our case with remission using