Disease directory

Seborrheic dermatitis

Published: September 18, 2026Updated: September 18, 2026

Important: Informational content intended for healthcare professionals. It does not replace clinical evaluation or establish a doctor-patient relationship.

Section

Overview

Sections

Overview

Names. Seborrheic dermatitis (SD), seborrheic eczema; dandruff/pityriasis capitis for the mild scalp form; cradle cap in infants.

First description. Described as a clinical entity in the 19th century (e.g., Unna, 1887) and consolidated in subsequent historical reviews.

Epidemiology (adults and children).

Point global prevalence ~4–6% (multicenter meta-analysis); peaks in early lactation and in young adults and >50 years.
Slight male predominance; increase in cold climates/winter; chronic-recurrent course.
Associations: HIV infection (prevalent, with extensive and refractory forms), Parkinson’s disease (frequent), and other comorbidities (e.g., psychiatric mood/stress disorders, seborrhea).

Codes.

ICD-10: L21.0 (pityriasis capitis), L21.1 (childhood DS), L21.8 (other), L21.9 (unspecified).
ICD-11: EA81 (Seborrheic dermatitis) and subcategories by location.