Skin Presentations

Presentations where the skin is the first or most visible clue to a systemic genetic disorder. Reasoning is consistently pattern + distribution + age of onset: pigmentary lesions distribute along Blaschko's lines, follow embryonic neuroectoderm migration, or scatter randomly; tumors cluster around nerves, hair follicles, or sebaceous units; blistering tracks with trauma sites and fragility planes. The skin is often the entry point into a multisystem diagnosis (neurofibromatosis type 1, tuberous sclerosis, McCune-Albright, Bloom, CMMRD), so the dermatologic finding rarely stays a dermatology problem for long. Wood's lamp, dermatoscopy, family history of similar lesions, and a careful count and measurement of lesions are the bedside tools that earn their keep.