A report describes a case of a 45-year-old male patient who was a construction worker with no personal history of psoriasis, atopic dermatitis or vitiligo, who presented with chronic hand eczema and skin depigmentation over 12 months. Regarding primary eczema, he reported the occurrence of skin depigmentation a few months later. He also reported the use of rubber gloves for many years. 

The patient reported itching and mild erythema over both hands and used nitrile gloves at work. Physical examination revealed symmetric erythematous-squamous, hyperkeratotic and fissured plaques on both hands and the ventral aspect of wrists. The depigmented areas had irregular edges. 

Wood′s lamp examination accentuated depigmentation areas overlapping eczema without a vitiligo pattern. No other anatomical sites were involved.

Blood examinations (including tests for autoimmune thyroiditis, celiac disease and pernicious anemia) revealed no significant alterations. Patch tests performed and read on the 2nd and 4th day showed a strong positive reaction to mercaptobenzothiazole (MBT). Also, the patch test results performed with a piece of glove that the patient previously used showed a positive reaction on day 2 and day 4. 

Histological examination showed an orthokeratotic epidermis of slightly reduced thickness with a conserved ridge pattern with hypopigmentation and a significant decrease in the melanocytes. Depigmented lesions showed an absence of Melan-A, S100, and HMB-45 staining.

Three and 6 months follow-ups showed a slight depigmentation in the MBT testing area.

The patient was diagnosed with contact vitiligo following allergic contact dermatitis caused by MBT and received treatment with UVB-narrowband phototherapy. He almost completely improved his eczema and depigmented areas at the 6-month follow-up.

Source: Ruiz-Villaverde R, Navarro-Triviño FJ. Contact vitiligo following allergic contact dermatitis. Sultan Qaboos Univ Med J. 2022;22(1):152-3.