Hypertrophy in port-wine stains: prevalence and patient characteristics in a large patient cohort.

BACKGROUND: Port-wine stains (PWS) may thicken and darken with age. Little is known about the pathogenesis and epidemiology of PWS hypertrophy because of the lack of large studies.
OBJECTIVE: We sought to assess the prevalence and characteristics of patients with hypertrophic PWS.
METHODS: Medical records and clinical photographs of all patients with PWS visiting our clinic between 2005 and 2009 were examined to identify hypertrophy. Patients were sent questionnaires regarding their hypertrophic PWS.
RESULTS: In all, 335 patients (age 0-81 years; 69% female) with PWS were included. Hypertrophy was found in 68 patients (20%; 32 male, 36 female) and classified as thickened (5%), nodular (8%), or both (7%). Color of hypertrophic PWS was mainly red (50%) or purple (44%). Patients with hypertrophy in their PWS were mostly (68%) older than 40 years, and rarely (7%) younger than 20 years. When older than 50 years, 71% of all patients had hypertrophy in their PWS. Median age of onset of PWS hypertrophy was 31 years (12 years for thickened, 39 years for nodular). LIMITATIONS: This was a retrospective study in a selected population.
CONCLUSION: Hypertrophy is an important feature in the development of PWS and affects a majority of patients older than 50 years. Depth of color of the PWS is associated with hypertrophy, whereas location and size appear not to be related. More attention should be drawn to therapy and prevention of hypertrophic PWS. Diffuse thickening and nodules should be distinguished, as a different age of onset may indicate different pathomechanisms.