Congenital curvilinear palpable hyperpigmentation

Sock-Line Hyperpigmentation: Case Series and Literature Review

“…Our cases of sock-line hyperpigmentation closely resemble the 2 cases of congenital curvilinear palpable hyperpigmentation reported by Zhu et al 1 Our patients have not demonstrated the neurologic abnormalities experienced by 1 patient described by Zhu et al 1 Based on the 7 reported cases, sock-line hyperpigmentation is acquired and usually arises in infancy. It may occur in either sex, in black or white children, and may be unilateral or bilateral, circumferential or limited to the calf, and palpable or flat.…”

“…1 We report a case of AGEP associated with recreational drug use-namely, cocaine or marijuana. 1 We report a case of AGEP associated with recreational drug use-namely, cocaine or marijuana.…”

Sock-line bands in infancy

“…Sock‐line hyperpigmentation may be uni‐ or bilateral, circumferential or limited to the calf, palpable or flat, single or multiple 1,2 . The case here suggests that patients may present after the hyperpigmentation has resolved, with palpable, skin‐coloured lesions.…”

“…We hypothesized that tight elastic bands of socks or pant legs may cause inflammation in the dermis or fat, which may heal with postinflammatory changes resembling sock lines. Only seven cases of sock‐line hyperpigmentation have been reported, including two infants described by Zhu et al 2 . as ‘congenital curvilinear palpable hyperpigmentation’.…”

Sock-line hyperpigmentation in infancy

“…Three reported cases were biopsied, which demonstrated postinflammatory hyperpigmentation 2 and lentiginous melanocytic hyperplasia. 3 The aetiology is not clearly understood, but it is thought to relate to dermal inflammation or panniculitis caused by sustained compression, resulting in postinflammatory hyperpigmentation.…”