FROM PEDIATRIC DERMATOLOGY

A case series of seven girls with apparent vitiligoid lichen sclerosus supports the possible predisposition of this condition in darker skin types, said Margaret H. Dennin, of the University of Chicago, and her associates.

Vitiligoid lichen sclerosus is a superficial variant of lichen sclerosus (LS), in which the lesion clinically appears to be vitiligo, but histologically is consistent with LS.

Seven dark-skinned girls aged 3-9 years had symptomatic (pruritus, pain, bleeding, constipation) depigmented patches of the vulvar or perianal region; three had purpuric lesions. None of the patients had atrophy or scarring, and they had no depigmentation anywhere else on their bodies. Follow-up was an average 2 years (range 3 months to 4 years).

Treatment with high-potency topical steroids, calcineurin inhibitors, or both resulted in improvement or resolution of their symptoms in all cases, but there was mild or no improvement in the depigmentation. Biopsies were not performed because of the patients’ young age and the location of the lesions, the investigators said.

The term vitiligoid lichen sclerosus was first coined in 1961 by Borda et al. when depigmented patches, as seen in both conditions, constituted the clinical appearance, but lacked the inflammation, atrophy, and sclerosis of typical LS. Histologically, these lesions were like LS, “based on the presence of a thin band of papillary dermal sclerosis,” Ms. Dennin and her associates said. Borda et al. suggested that vitiligoid lichen sclerosus might be limited to dark-skinned people, and recent reports support this. Alternatively, it may be that the depigmentation simply is more obvious on dark-skinned people, and asymptomatic cases go unnoticed on lighter-skinned people, the investigators surmised.

Both vitiligo and LS are autoimmune cutaneous disorders, and they both often affect the anogenital region. The conditions “may be linked through a common autoimmune response from exposed intracellular or altered cell surface antigens on damaged melanocytes,” the investigators said. “Histologic evidence demonstrates that development of vitiligo involves a preceding lichenoid inflammatory reaction that may trigger an autoimmune reaction to melanocytes, decreasing their number. Evolving vitiligo with a lichenoid reaction may result in epitope spreading and the development of LS.”

The study is limited by its retrospective nature, small sample size, and lack of biopsies, the researchers noted. Larger studies are needed to look at the overlap of the conditions, and “understand the true prevalence of vitiligoid lichen sclerosus,” Ms. Dennin and her associates said.

Read more in Pediatric Dermatology ( 2018. doi: 10.1111/pde.13399 ).

cnellist@frontlinemedcom.com

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