Frictional melanosis

Friction melanosis; skin melanosis; hyperpigmentation; 

w>m.

Chronic mechanical irritation, e.g., caused by nylon towels or brushes

In a larger study, the age range was 18 to 59 years, with most patients between the ages of 20 and 35.

The pigmentation typically exhibited a wavy pattern on the upper back and collarbone area, a zebra-like pattern across the ribs, and stamp-like patches of pigmentation along the spine.

No signs of inflammation; melanin deposits in the upper dermis.

Pigmentary Disorders of Other Origins

Notalgia paraesthetica: Localized in the area of the shoulder blades; itching sensation 

Macular amyloidosis: Histological evidence of amyloid 

In 1984, Hidano A et al. described 23 otherwise healthy patients with brownish pigmentation that appeared over bony structures such as the clavicle, scapula, or vertebrae.

The group consisted of 19 women and 4 men. Their ages ranged from 18 to 59 years, with most patients between 20 and 35 years old.

Since the first observation in 1977, the number of cases has gradually increased.

The pigmentation typically exhibited a wavy pattern in the upper back and clavicular regions, a zebra-like pattern over the ribs, and stamp-like pigmented patches along the spine.

Although there were no signs of inflammation, such as itching or scaling, histological examination revealed post-inflammatory melanin deposits in the upper dermis.

1. Al-Khidour, M., et al. (2004) Friction melanosis: a clinical, histologic, and ultrastructural study in Jordanian patients. International Journal of Dermatology DOI: 10.1111/j.1365-4632.2004.01606.x.
2. Bansal A et al. (2023) Current understanding of frictional dermatoses: A review. Indian Journal of Dermatology, Venereology, and Leprology 89:170–188.
3. Hidano A et al. (1984) Frictional melanosis. Ann Dermatol Venereol. 111:1063–71.
4. Holzer D et al. (2021) Frictional melanosis: A pediatric case series. Pediatr Dermatol 38:1345–1346.
5. Kowalski A et al. (2024) Davener’s dermatosis: a unique presentation of frictional hypermelanosis. J Osteopath Med 124:463–464.
6. Shendrik I et al. (2025) Acral Melanosis with Macromelanosomes (AMM): The First AI-Defined Pathological Entity and Proposal of Provisional Diagnostic Criteria. Cureus 17:e97276.
7. Siragusa M et al. (2001) Friction melanosis, friction amyloidosis, macular amyloidosis, towel melanosis: many names for the same clinical entity. Eur J Dermatol 11:545–548.
8. Yoon JH et al. (2021) A Rare Case of Transient Friction Melanosis of the Finger: A Case Report. Ann Dermatol 33:568–571.