Background and aim: Macular amyloidosis (MA) is a form of primary localized cutaneous amyloidosis (PLCA), characterized by amyloid deposits in the papillary dermis. This study aimed to compare the biophysical properties of MA lesions with those of adjacent uninvolved skin.
 

Methods: We measured several parameters in active MA lesions of 22 patients, including stratum corneum (SC) hydration, transepidermal water loss (TEWL), surface friction, pH, sebum, melanin, erythema, temperature, elasticity parameters (R0, R2, and R5), as well as epidermal and dermal thickness and echo-density using ultrasonography. Measurements from the lesions were compared with those from healthy skin adjacent to the lesions, serving as controls. Statistical analysis was performed using the paired t-test, with P-values less than 0.05 considered significant.
 

Results: Compared to adjacent normal skin, MA lesions demonstrated significantly lower SC hydration and surface friction, while TEWL, pH, erythema index, melanin content, and epidermal thickness were significantly increased. No significant differences were found in sebum levels, temperature, elasticity parameters, or dermal thickness and echo-density.
 

Conclusion: MA lesions exhibit distinct biophysical and ultrasonographic changes consistent with their histopathological features. These characteristic alterations may serve as useful, non-invasive markers for the early diagnosis of cutaneous macular amyloidosis.