Friction melanosis
A form of acquired hyperpigmentation in children caused by repetitive mechanical friction to the skin, most commonly over bony prominences, resulting in post-inflammatory pigmentary change.
Full Definition
Friction melanosis (also called nylon washcloth melanosis or towel melanosis in some regional literature) occurs when chronic rubbing—from rough bathing cloths, tight clothing, or habitual scratching—induces pigmentary changes in the epidermis and superficial dermis. In pediatric populations it is seen particularly in darker skin phototypes and may affect the spine, clavicles, elbows, and knees. The condition is not associated with systemic disease but may be confused with other causes of patterned hyperpigmentation, including linear IgA dermatosis, erythema ab igne, or metabolic pigmentation disorders. Editorial accuracy requires preserving the causative qualifier 'friction' and not substituting generic terms such as 'hyperpigmentation' or 'melanosis' without qualification.
Usage
Usage note: Retain the qualifying adjective 'friction' in all uses; 'melanosis' alone is insufficiently specific in dermatology manuscripts. Regional synonyms (nylon washcloth melanosis) may be noted parenthetically but should not replace the preferred term.
In Context
- "The dermatologist documented friction melanosis along the child's spine, attributing it to vigorous rubbing with a loofah during bathing." — Outpatient pediatric dermatology clinic note
- "When editing tables of differential diagnoses for childhood hyperpigmentation, friction melanosis should be listed separately from postinflammatory hyperpigmentation, as the mechanism and management differ." — Medical textbook chapter edit