A clinicopathologic study of cutaneous amyloidosis at a tertiary health care center in South India

Abstract

Background: Primary cutaneous amyloidosis (PCA) is quite a common disorder seen in Southeast Asia. It is characterized by amorphous eosinophilic deposits of a fibrillar protein in the dermis without any systemic involvement. However, the etiology for this disease still remains elusive without much satisfying outcomes with the currently available treatments. Aim: To study the clinical and demographic patterns of PCA and correlate it with histopathological findings along with polarized microscopy examination. Methods: A cross-sectional study done over a 1½ years period wherein after patient enrollment, they underwent a thorough clinical evaluation followed by a skin biopsy and complemented by polarized microscopy. Results: A prevalence of 0.04% and a female preponderance (61.76%) was observed. Lichen amyloidosis (LA) was more common than macular amyloidosis (MA). Majority of patients presented between 41 and 50 years. There was a significant association of pruritus and friction with PCA. The most common sites involved were shins for LA and interscapular area for MA. On histology, epidermal changes were not so significant for MA. However, hyperkeratosis and acanthosis were major epidermal findings for LA. Lymphohistiocytic infiltrates were common dermal changes for both variants of amyloidosis. Amyloid deposits appeared as eosinophilic fissured masses under light microscopy on hematoxylin and eosin staining. Conclusion: PCA is a disorder of middle age seen more commonly in females. Pruritus and friction demonstrate significant contribution in the development of PCA. Whether there is an association of PCA with diabetes mellitus, hypertension, bronchial asthma, and hypothyroidism needs further consideration.