Neurocutaneous disorders and other syndromes
Certain inherited skin disorders also have significant involvement of internal organs. The neurocutaneous disorders, the inherited diseases of connective tissue and the premature ageing syndromes are included.
Neurofibromatosis
Clinical presentation
The two main cutaneous features are:
1. Café-au-lait spots: round or oval coffee-coloured macules, due to increased melanin pigment. They often appear in the first year of life. One or two café-au-lait spots are seen in 10% of normal people but, in neurofibromatosis, six or more are usually present. Freckling of the axilla is also found (Fig. 1).
2. Dermal neurofibromas: small nodules that appear during childhood and increase in number at the time of puberty (Fig. 2). Their number varies from a few to several hundred.
Complications
Complications develop in many cases and include the following:
Plexiform neurofibromas are larger than their dermal counterparts and measure up to several centimetres in size. They are associated with pigmentation and hypertrophy of the overlying skin or underlying bone, and present a cosmetic problem.
Sarcomatous change in a neurofibroma, typically non-cutaneous, occurs in 1.5–15% of cases.
Kyphoscoliosis (in 2%) or bowing of the tibia and fibula may occur.
Management
Once the diagnosis has been made, genetic counselling and the exclusion of any complicating factors are important. Troublesome nodules can be excised, and larger disfiguring neurofibromas removed by plastic surgery. Patients are often helped by contact with a patient support group (p. 132).
