Clinicopathological study of primary cutaneous amyloidosis in a tertiary care center of Eastern India reveals insignificant association with friction, scrubbing, and photo-exposure: How valid is the “keratinocyte hypothesis”?

Abstract

Introduction:Primary cutaneous amyloidosis (PCA) can be classified into four principal categories: macular amyloidosis, lichen amyloidosis, biphasic, and nodular amyloidosis. Some unusual variants such as widespread diffuse hyperpigmentation without papules, poikiloderma like involvement, lesions following Blaschko's line, etc., have also been reported. However, not much data are available regarding the demography, epidemiology, clinical patterns, and distribution and histopathological findings, especially from the eastern part of India.Aims:We conducted a cross-sectional, institution-based study to evaluate clinicopathological pattern and factors of PCA in eastern India.Materials and Methods:We recorded clinical and histopathological findings of 100 consecutive patients of PCA presenting to a tertiary care institution of Kolkata in eastern India.Results:We found female patients of PCA outnumber male (M:F =1:1.9) with majority of patients being young adults (56%) between 20 and 40 years of age. More than half (54%) of the patients were pruritic. The severity of pruritus is significantly more associated with lichenoid and biphasic variants over macular amyloidosis. Positive family history was recorded in 17% of cases. Macular variant was the most common variant constituting 48% of the total PCA. We also found that the association with history of friction and scrubbing and photo-exposure were statistically insignificant. However, duration of the disease has statistically significant association with the disease morphology. Congo red stain showed these deposits as reddish orange substance in 28 patients out of 64 patients’ samples on which Congo red could be performed.Conclusion:Our study revealed that many concepts of pathogenesis of PCA including friction and photoexposure might have lesser importance. However, morphological types were significantly associated with the duration of the disease and symptom severity.

Primary Localized Cutaneous Amyloidosis in Central Europe: A Retrospective Monocentric Study on Epidemiology and Therapy

“…The aim of this monocentric retrospective study was to analyze primary localized cutaneous amyloidosis in the Central European region concerning demographic data, body distribution, comorbidities, treatment practices and treatment outcomes. While PLCA is more prevalent in Asian and South American populations, epidemiologic data regarding PLCA in the Caucasian population are limited [2,3,[55][56][57].…”

Barrier function and ultrastructure characteristics of epidermis in patients with primary cutaneous amyloidosis

“…The etiology of PCA remains unclear although genetic predisposition, approximately 10% of patients have a family history of PCA 3 . Racial factors, gender, atopy, sun exposure, and frictional epidermal damage are also thought to contribute to the etiopathogenesis 4 . Studies have shown that the occurrence, development, and aggravation of many skin diseases are closely related to the destruction of skin barrier structure 5 .…”

“…3 Racial factors, gender, atopy, sun exposure, and frictional epidermal damage are also thought to contribute to the etiopathogenesis. 4 Studies have shown that the occurrence, development, and aggravation of many skin diseases are closely related to the destruction of skin barrier structure. 5 Once any tissue or chemical composition in the skin barrier is abnormal, it will trigger the etiology and pathological process of clinical skin diseases.…”

Characterization of Epidermal Function in Individuals with Primary Cutaneous Amyloidosis

“…4 Factors such as race, gender, atopy, sun exposure, and the debated frictional epidermal damage have also been proposed as contributors to its etiopathogenesis. 5 Treating PCA remains a formidable challenge for clinicians due to the absence of evidence-based treatment guidelines. Many treatment avenues have been explored, spanning retinoids, corticosteroids, cyclophosphamide, laser treatment, and phototherapy, etc.…”