Amyloidosis is formed following deposition of protein aggregates and is classified by systemic or cutaneous deposition. These aggregates can be distributed in different organs such as the heart, liver, lungs, kidneys, and skin. Primary cutaneous amyloidosis has been classified into three groups: macular, lichen, and nodular, the former two being one often overlapping process, and the latter a localized plasma dyscrasia with a small risk of representing a systemic disease. Historically, cutaneous amyloidosis has been misdiagnosed, and most treatment regimens have been ineffective or only provide supportive management, such as decreasing pruritus. The current standard of care, high-potency corticosteroids, can provide symptomatic relief. Newer therapies may decrease amyloid deposition and progression of disease.

Brachioradial pruritus (BRP) and macular amyloidosis (MA) are distinct dermatological conditions that have rarely been reported together. BRP is a neuropathic pruritus affecting the lateral forearm, whereas MA presents as hyperpigmented patches caused by amyloid deposition in the dermis. We report the first case of synchronous MA and BRP in a 45-year-old woman who presented with severe pruritus in the brachioradialis distribution, concurrent with hyperpigmented patches characteristic of MA. Cervical spine imaging revealed moderate-to-severe multilevel degenerative changes. The patient was successfully treated with gabapentin 200 mg daily, with significant improvement in both conditions. This case highlights the first reported synchronous presentation of MA and BRP and suggests potential shared pathophysiological mechanisms. The favorable dual therapeutic response to gabapentin provides new insights into management strategies for concurrent presentations of these conditions.

Patchy pigmentation of lower legs presents with patches of hyperpigmentation, hypo, or depigmentation of legs. Dermoscopy is an efficient diagnostic tool dermatologists use to bridge the clinical and histological evaluation gap. This study on lower leg pigmentation is probably the first report from India. To study the clinical, dermoscopic, and histopathological features of patchy pigmentation of lower legs in patients presenting to our Out-Patient Department (OPD). This was a cross-sectional descriptive study done on 150 patients with patchy pigmentation of lower legs in patients above the age of 18 years attending the dermatology OPD, JIPMER, during the study period of March 2022 to December 2023 by convenient sampling. A detailed history was taken and a detailed dermatological examination was performed. Dermoscopy and skin biopsy for histopathological examination was performed and recorded in a proforma. The mean age of the cases was found to be 52.3 (±14.06) years (ranged from 18 to 97 years) with female:male ratio of 1.7:1. Among 150 cases, 127 (84.66%) cases had patchy hypopigmentation and 23 cases (15.33%) had patchy hyperpigmentation of lower legs. Among 127 cases of patchy hypopigmentation of lower legs, idiopathic guttate hypomelanosis (IGH) was the most common cause found in 61 (48.81% cases), followed by vitiligo (32, 25.19% cases), and post-inflammatory depigmentation (29, 22.65% cases). Among 23 cases of patchy hyperpigmentation of lower legs, pigmented purpuric dermatosis (PPD) was the most common cause seen in 12 (52.17% cases), followed by post-inflammatory hyperpigmentation (10, 43.47% cases). The most common dermoscopic pattern was amoeboid (21, 33.87%) in IGH, white structureless areas (31, 96.9% cases), followed by perifollicular pigmentation (18, 56.3% cases) in vitiligo and red dots (10, 83.3%) in PPD. Nearly 85% of lower leg pigmentation cases were hypopigmentary. Amongst hypopigmentary disorders, nearly 50% of cases were of idiopathic guttate hypomelanosis, followed by others like vitiligo, post-inflammatory depigmentation, contact leukoderma, nevus depigmentosus, and hypopigmented macular amyloidosis. Dermoscopic features of vitiligo and post-inflammatory depigmentation were similar. Pigmented purpuric dermatosis was the most common cause of hyperpigmentary disorders of the lower legs, followed by post-inflammatory hyperpigmentation and macular amyloidosis.

Primary cutaneous amyloidosis (PCA) lacks consensus-based therapeutic guidelines, with conventional modalities demonstrating suboptimal clinical responses. To assess the efficacy and safety profile of oral tofacitinib, a Janus kinase 1/3 inhibitor, in PCA management. This single-centre, open-label, single-arm prospective interventional study enrolled 20 patients with PCA receiving tofacitinib 5 mg twice daily. Demographic parameters, disease characteristics [measured using the pruritus numeric rating scale (p-NRS), Dermatology Life Quality Index (DLQI) and Lesion Severity (LS) scores], and adverse events were systematically recorded at baseline and weeks 2, 6 and 10 post-treatment. At week 10, significant reductions were observed across all endpoints: p-NRS from 6.9 (SD 2.9) to 0.4 (SD 0.6, P < 0.001); DLQI from 11.8 (SD 5.6) to 2.6 (SD 2.5, P < 0.001); and LS from 13.3 (SD 5.2) to 4.9 (SD 2.4, P < 0.001). Patients with lichen amyloidosis (8 of 15) and biphasic amyloidosis (3 of 3), but neither of the 2 patients with macular amyloidosis, achieved the primary efficacy threshold. Two treatment-emergent adverse events occurred; these were transient hepatobiliary enzyme elevations resolving with hepatoprotectants and one patient with a self-limiting upper respiratory infection. Tofacitinib demonstrates rapid antipruritic effects and sustained lesion clearance in PCA, with favourable tolerability. Study limitations, including the small sample size (n = 20), 10-week duration and uncontrolled design, which may limit generalizability, warrant phase III trials for validation.

Macular amyloidosis (MA) is a primary localized cutaneous amyloidosis (PLCA), characterized by amyloid deposition in the papillary dermis. The goal of this study was to compare biophysical characteristics in MA lesions with uninvolved skin. Stratum corneum (SC) hydration, transepidermal water loss (TEWL), surface friction, pH, sebum, melanin, erythema, temperature, elasticity parameters (R0, R2, and R5), thickness, and echo-density of epidermis and dermis were measured on the active MA lesions in 22 patients and compared with the healthy area adjacent to the lesion as control. Paired t-test was used for statistical analyses, and a p < 0.05 was considered significant. SC hydration, skin friction were significantly lower, whereas TEWL, pH, erythema index, melanin content, and the thickness of epidermis were significantly higher in MA lesions. There was no significant difference in other biophysical and ultrasonographic parameters between MA and normal skin. MA lesions are characterized by specific changes in ultrasonographic and biophysical parameters, compatible with their histological features. These charachteristics are likely to be useful in the early and noninvasive detection of cutaneous MA in the future.