Segmental vitiligo and extragenital lichen sclerosus et atrophicus simultaneously occurring on the opposite sides of the abdomen.

Abstract

Dear Editor: A 10-year-old female patient visited the dermatology clinic because of hypopigmented skin lesions on both sides of her abdomen that occurred 3 years ago (Fig. 1A, B). There were no associated symptoms or history of infectious diseases, stressful events, or trauma. Her parents did not recall any history of familial autoimmune diseases. Laboratory tests on autoimmune panels (antinuclear antibody, anti-DNA screening, anti-Scl 70) were all negative. On Wood's light examination, hypopigmented lesions on the right abdomen showed marked accentuation that was clinically consistent with segmental vitiligo (SV). On the other hand, the lesions on the left side of the abdomen revealed only mild accentuation. Whereas biopsy was not performed on the lesion suspicious for SV, histopathological examination of a hypopigmented plaque on the patient's left abdomen showed follicular plugging and fibrosis with edema in the upper dermis, suggesting lichen sclerosus et atrophicus (LSA) (Fig. 1C, D). Although rare, there are incidences of morphea presenting with vitiligo, requiring attentive differential diagnosis with LSA. Yet, features that suggest morphea, such as thickened collagen bundles or atrophic eccrine glands, were not seen. Fig. 1 (A) Well-demarcated hypopigmented patches without surface changes on the right abdomen. (B) Multiple hypopigmented papules and plaques occurring with atrophic surface change and hardening on the left abdomen. The lesions shown in both (A) and (B) had ... There have been previous reports of SV and LSA occurring simultaneously. However, most of the reported cases were SV that co-occurs with genital LSA1,2 or extragenital LSA in a non-SV (NSV) patient3. Thus, to our knowledge, we here report the first case of extragenital LSA occurring with SV. The significance of LSA and SV of synchronous onset can be interpreted as a deviation from a previously known mechanism for SV. Also, we believe that it suggests a possible relation between the mechanisms of two very different diseases. Although an exact pathomechanism for LSA is not yet known, there is an unproven consensus that LSA is an autoimmune disease, on the basis of evidences such as the presence of circulating antibodies targeting extracellular matrix protein 1 and the frequent association of LSA with other autoimmune diseases4. Concerning SV, although it is mostly thought to involve a neural mechanism, there is a view that an autoimmune basis adds to its onset as well. A case report on SV occurring concurrently with alopecia areata, psoriasis, and halo nevus supports this hypothesis, as the three diseases except SV are known to have an autoimmune basis5. Hence, from our interesting case of SV and LSA occurring on the opposite sides of the abdomen along Blashko's line, we suggest that there is a possibility of a common initiating factor or a shared pathomechanism existing between SV and LSA. Furthermore, if autoimmunity or auto-inflammatory reaction takes place in the onset of SV, our case could provide supporting evidence for SV sharing a common link with NSV.