When characterizing IP, the only major criteria are four incontinentia pigmenti (IP) stages. Each stage is outlined below, but note that they can overlap. Visit our Incontinentia Pigmenti Treatment page to learn more about taking care of skin, hair and other affected areas.

Incontinentia Pigmenti Stages

Stage 1

  • Onset birth-newborn period
  • Skin erythema, vesicles, pustules
  • Affects limbs and trunk
  • Occurs in linear distribution

The first incontinentia pigmenti stage is the erythematous (red) and vesicular (blister-like) stage which appears in infancy and is often present in the newborn. This consists of redness, blisters, and boils. It is the initial manifestation in 90% of patients. It may last from a few weeks to a few months. For this reason, it is often confused with a viral rash and infants may be placed in isolation and treated with antiviral drugs until the diagnosis of IP is confirmed either by skin biopsy, blood counts (high eosinophil counts) or molecular genetic studies.

incontinentia pigmenti stages

The extremities, torso, and the scalp are most often affected. But, the rash can be present on any body part. It may recur at times in the first few months of life, but rarely ever later. As serious as it looks, the rash does not seem to be painful, though clothing may irritate the blisters.

Stage 2

  • Skin papules
  • Wart-like (verrucous) lesions
  • Thickened skin patches (hyperkeratosis)
  • Affects distal limbs and scalp

The second incontinentia pigmenti stage, which may overlap with the first, are blisters which evolve with a raised verrucous (wart-like) surface. The lesions look like pustules. There can be thick crusts or scabs with healing and areas of increased pigmentation (darkened skin). 

The second phase may be present at birth (implying that the vesicular stage 1 took place in the womb), but it usually evolves after the first stage in ~70% of patients. The extremities and back are involved almost exclusively. This stage typically lasts months, but rarely as long as a year.

Stage 3

  • Skin hyperpigmentation
  • Primarily affects trunk
  • Follows Blaschko’s lines
  • Streaks and whorls
  • Fades in adolescence

The third incontinentia pigmenti stage is the hyperpigmented stage in which the skin is darkened in a swirled pattern often described as a “marble cake” appearance. In some patients, the adjacent areas ultimately thin and widen leaving streaky hypopigmentation. 

incontinentia pigmenti stages - stage 3

It may be present at birth in 5-10% of patients but usually appears between 6 and 12 months of life. The third stage persists for several years and usually disappears at about age 20 years.

This may or may not correspond to the areas that were involved in Stages 1 and 2. The heavy pigmentation tends to fade with age (decades) in most affected individuals.

Stage 4

  • Skin pallor, atrophy, and scarring
  • Reduction of hair in the involved scarred areas, both on the limbs and scalp
  • Most evident on lower legs

The fourth incontinentia pigmenti stage is the atrophic (scarred) stage. These scars often are present before the hyperpigmentation has faded. They appear on adolescents and adults as pale, hairless patches or streaks. These are most easily seen when they are on the calf or in the scalp. Once most patients reach adulthood (late teen and beyond), the skin changes may have faded and may not be visible to the casual observer.