Hypomelanosis of Ito

Dr Yair Glick and Dr Bruno Di Muzio et al.

Hypomelanosis of Ito, also known as incontinentia pigmenti
achromians
, is the third most frequent phakomatosis, involving a wide spectrum of defects in multiple organ systems.

The prevalence is unknown, being reported as between 1 per 8000 patients in a general pediatric hospital 3 and 1 per 600–700 patients referred to a pediatric neurology service 1.

As a neurocutaneous disease, the skin lesions are remarkable and are present in the first year of life in ~70% of patients. Lesions manifest as hypopigmented zones or spots with irregular borders, sometimes whorls, or linear white streak lines following Blaschko’s lines. Other cutaneous-associated manifestations include café-au-lait spots, cutis marmorata telangiectatica congenita (CMTC), angiomatous nevi, Mongolian blue spot, and nevus of Ota. Iris hypopigmentation is also reported. It is important to note that the disease severity is not correlated with the extent of cutaneous lesions 1.

Changes in hair color, diffuse alopecia and hair with trichorrhexis nodosa are reported as scalp manifestations of this disease.

Extracutaneous manifestations:

  • mental retardation and epilepsy: seizures commonly appear early and generally are refractory to anticonvulsant drugs
  • a variety of non-specific ocular alterations
  • dental: defective dental implantation, conical teeth, partial anodontia, and hypodontia
  • musculoskeletal disorders, such as hypotonia
  •  occasional association with benign tumors, including

The exact cause of hypomelanosis of Ito is unknown with many cases being associated with genetic mosaicism and sporadic gene mutations.

The hypopigmented lesions are the result of a decrease in the number of melanocytes and in the number and size of melanosomes 1.

CT and, more clearly, MRI can demonstrate several abnormalities.

Hypomelanosis of Ito has been associated rarely with vascular anomalies such as Moyamoya syndrome or intracranial arteriovenous malformation.

There is no specific treatment; treatment is based on symptomatology.

Was described by Minor Ito (1884-1982), Japanese dermatologist, in 1952 2.

The most commonly confused diagnosis is with incontinentia pigmenti, a rarer phakomatosis.

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Article information

rID: 32151
Section: Syndromes
Tag: cases
Synonyms or Alternate Spellings:
  • Incontinentia pigmenti achromians
  • Ito hypomelanosis

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