Xeroderma Pigmentosum

XP (Children of the Moon)

Overview

Xeroderma pigmentosum (XP) is a rare, inherited genetic disorder caused by defects in the DNA repair mechanism that fixes ultraviolet (UV) radiation damage. Affected individuals are extremely sensitive to sunlight and have a dramatically increased risk of developing skin cancers at a very young age. Strict sun protection from birth is the cornerstone of management.

Key Symptoms

  • Severe sunburn with blistering after minimal sun exposure, often noted in infancy
  • Numerous freckle-like spots (lentigines) appearing in sun-exposed areas before age 2
  • Dry, parchment-like skin (xerosis) in sun-exposed areas
  • Very early onset of skin cancers (basal cell, squamous cell, melanoma) — often before age 10
  • Progressive photodamage with telangiectasias, atrophy, and irregular pigmentation
  • Eye problems including photophobia, conjunctival inflammation, and corneal damage

Affected Areas

Face, Neck, Arms, Hands, Any sun-exposed skin, Eyes

Care Instructions

  1. Strict, lifelong UV protection is essential: avoid all sun exposure and UV light sources.
  2. Wear UV-protective clothing, broad-brimmed hats, UV-blocking glasses, and UV-filtering window film.
  3. Apply broad-spectrum SPF 50+ sunscreen to all exposed skin, reapplying frequently.
  4. Regular skin exams (every 3-6 months) with a dermatologist for early detection and treatment of skin cancers.
  5. Regular ophthalmologic exams to monitor for UV-related eye damage.
  6. Genetic counseling for families; XP is inherited in an autosomal recessive pattern.

Medical Disclaimer: This information is for educational purposes only and does not replace professional medical advice. Always consult a qualified dermatologist for diagnosis and treatment.

Prevalence: Very rare; approximately 1 in 250,000 people in the United States