Riehl's melanosis-like eruption associated with Sjögren's syndrome

Coexistence of Riehl's Melanosis, Lupus Erythematosus and Thyroiditis in a Patient

Introduction

Riehl’s melanosis (RM) is an acquired hyperpigmentation disorder, presenting diffused and reticulate brownish-gray pigmentation, preferentially on the face and neck. RM overlaps with systemic lupus erythematosus (SLE) and Hashimoto’s thyroiditis has never been reported.

Case

We report a case of RM patient accompanied with SLE and Hashimoto’s thyroiditis of primary hypothyroidism. Progressing, diffuse, symmetric, and reticular hyperpigmentation was seen on the face, neck, and upper limbs, manifesting as typical melanosis. Skin microscopy showed diffuse black-pepper-like changes and telangiectasias. The diagnosis of SLE and primary hypothyroidism were confirmed by follow-up investigations. The hyperpigmentation turned notably lighter after 14 months of treatment with prednisone, hydroxychloroquine, and L-thyroxine.

Discussion

The exact pathogenesis of RM is unclear and exposure to coal tar dyes, ultraviolet, and fragrance fixatives in cosmetics are believed to be contributing factors, while some cases involve no triggers. It is not impossible that RM is a rare skin manifestation of SLE that has never been reported. The skin hyperpigmentation in this patient was not triggered by thyroid disease.

Conclusion

RM could be a skin manifestation of autoimmunity. Coexistence of RM, lupus erythematosus and thyroiditis in the same patient is rare and has never been reported.

Three cases of pigmented cosmetic dermatitis-like eruptions associated with primary Sjögren's syndrome or anti-SSA antibody

Pigmented cosmetic dermatitis-like (Riehl's melanosis-like) pigmentation was reported in three of 27 patients with primary Sjögren's syndrome. But case reports of such eruptions are rare. We describe three cases of such eruptions associated with primary Sjögren's syndrome or anti-SSA antibody and possible associations with specific types of human leukocyte antigen (HLA) and infiltrating lymphocytes. These middle-aged Japanese women had reticular facial pigmentation and histopathological examination revealed interface dermatitis, melanophages, and dense lymphocytic infiltration around hair follicles and sweat ducts. HLA typing revealed common antigenic equivalents or genetic typing of HLA-A2, DR52, DPA1(02:02) and DPB1(05:01). Immunohistochemical staining revealed major subsets of T cells to be CD8 and CD45RO. Some Foxp3- and few IL17-positive cells were found in strong contrast to the major CD4 subset of infiltrated T cells in annular erythema associated with Sjögren's syndrome. Apparently, our patients' pigmentation represented a specific etiology associated with primary Sjögren's syndrome or anti-SSA antibody.