Phakomatosis: Definition, Causes, Symptoms and Treatment of This Neurocutaneous Disease

People with systemic involvement may have neurological, ocular (in the eyes), or muscle abnormalities.

Vascular pigment phakomatosis (VPP) is a disorder characterized by the coexistence of pigmented and vascular birthmarks.

Signs and symptoms may include port wine stain, melanocytic nevi  (commonly known as moles), epidermal nevi, dermal melanocytosis (areas of blue-gray discoloration), nevus spilus, and hyperpigmentation patches (areas of darker skin).

Other skin features may include nevus anemicus (areas of lighter skin) and café au lait spots.

About half of people with PPV have systemic involvement, which means they have characteristics that affect other areas of the body.

Several subtypes of PPV have been identified that are generally distinguished based on the specific type or types of skin features present.

Causes of phakomatosis

Isolated PPV is typically a sporadic disorder that occurs for the first time in people without a family history of PPV. Researchers have found that PPV can be caused by a somatic mutation in the GNA11  or  GNAQ gene    that is present only in affected tissues of the body.

These mutations are not present in the blood or unaffected tissues, meaning the disorder is likely due to inherited mutations that are acquired randomly after conception. In some cases of isolated PPV, the underlying cause remains unknown.

The treatment and long-term outlook (prognosis) of PPV largely depends on whether there is systemic involvement and which parts of the body or systems are affected.

Isolated PPV without systemic involvement generally does not require treatment. However, large skin lesions can cause problems with body image and self-esteem, so laser treatments may be considered to improve the appearance of skin lesions.

Symptoms of phakomatosis

The characteristic signs and symptoms of pigmentovascular phakomatosis (PPV) that affect the skin are the port wine stain and various pigmentary lesions (lesions that are brown, black, or blue in color).

Port wine stain and pigmentary lesions can be extensive and affect various areas of the body, including the face. Examples of associated pigmentary lesions include:

  • Melanocytic nevi (commonly known as moles).
  • Epidermal nevi.
  • Nevus anemicus (lighter skin areas).
  • Hyperpigmentation (darker skin areas).
  • Coffee with milk places.
  • Dermal melanocytosis (areas of blue-gray discoloration).
  • Nevus of Ota.
  • Nevo de Ito.
  • Nepo spilus.

About half of people with PPV have systemic involvement (that is, body systems other than the skin are affected). Eye conditions such as ocular melanosis (also called ocular melanocytosis) are common.

Ocular melanosis refers to a blue-gray pigmentation on the white of the eye (the sclera). This condition often occurs in conjunction with nevus of Ota and can affect one or both eyes.

Nevus of Ota complications include glaucoma and melanoma, so people with nevus of Ota require careful examination and follow-up by an ophthalmologist. Other eye conditions reported in PPV include iris hamartomas, iris mamelilla, and iris nodules.

When neurological abnormalities are present, they usually manifest in the first few months of life and may include developmental delay, seizures, intracranial calcifications (calcium deposits in the brain), or brain atrophy.

Some people with PPV also have Sturge-Weber syndrome or Klippel-Trenaunay syndrome, each of which causes a variety of signs and symptoms.

A variety of other signs or symptoms have been reported in individual cases of PPV (eg, primary lymphedema, renal angiomas, moyamoya disease, scoliosis, malignant colonic polyposis, hypoplastic larynx, multiple granular cell tumors, and selective IgA deficiency) .

The signs and symptoms associated with PPV can vary greatly from person to person and can be difficult to predict.

Treatment of phakomatosis

If pigmentovascular phakomatosis (PPV) is not associated with systemic complications (eg, Sturge-Weber syndrome, Klippel-Trenaunay syndrome, neurological problems, or eye conditions) it usually does not require treatment.

However, because large skin lesions can cause problems with body image and self-esteem, parents of children with PPV or adults with PPV may consider laser treatments to improve the appearance of skin lesions.

Lesions can grow in proportion to the body, so treatment is recommended as soon as possible in children with PPV to reduce the number of treatments needed and avoid self-esteem problems in future years.

Medical treatment for systemic complications depends on the signs and symptoms present in each person and may require an individualized treatment plan that involves a team of specialists in ophthalmology, neurology, and / or vascular surgery.