Recurrent inflammation of incontinentia pigmenti in a 30-year-old Woman

Incontinentia pigmenti (IP) is an X-linked dominant disorder with a complex multisystemic and developmental phenotype. Classically, the skin lesions occur perinatally in four successive stages: inflammatory vesicular (stage 1), verrucous (stage 2), hyperpigmented (stage 3), and scarring (stage 4), along the lines of Blaschko, reflecting the somatic mosaicism of X-chromosome inactivation in female patients. In general, the lesions of stage 1 IP begin perinatally and clear completely within the age of 4 months. We report a rare case of late recurrence of first stage lesions of IP in adulthood. This 30-year-old woman with a history of IP presented with multiple erythematous papules on pigmented patches distributing along the lines of Blaschko. Histological findings exhibited dyskeratosis in the epidermis along with perivascular and interstitial infiltrations composed of lymphocytes and eosinophils, consisting with the diagnosis of IP. In addition, we also review the recurrent cases with IP previously reported in the literature.