X-linked ichthyosis in Child
Alerts and Notices
SynopsisX-linked ichthyosis is an X-linked recessive disorder of abnormal cornification caused by a deficiency of steroid sulfatase, an enzyme that is needed for normal desquamation of the stratum corneum. It is classically characterized by dirty-appearing scale on the sides of the neck ("dirty neck") and the periumbilical area. The remainder of the trunk and extremities are also involved, with classic sparing of the face, palms, and soles, as well as the popliteal and antecubital fossae.
This condition is exclusively seen in males, appears before 3 months of age, and persists for life. During the first few weeks of life there is desquamation of large, loosely adherent, translucent scales followed by the development of tightly adherent, dark brown scales. The disease phenotype ranges from absent to marked and diffuse scaling. It is worse in low-humidity climates.
The disease may be diagnosed prenatally due to a low estriol on a maternal triple screen and confirmed by fluorescence in situ hybridization (FISH). Women with affected fetuses may experience lack of spontaneous labor and prolonged labor, possibly requiring cesarean delivery or vacuum-assisted delivery due to a lack of steroid sulfatase in the placenta, leading to decreased levels of estrogen and insufficient dilation of the cervix.
Q80.1 – X-linked ichthyosis
72523005 – X-linked ichthyosis with steryl-sulfatase deficiency
Differential Diagnosis & Pitfalls
- Ichthyosis vulgaris – Hyperlinear palms and soles, often associated with atopy.
- Lamellar ichthyosis – Tends to affect the entire skin surface, is usually more severe, and manifests ectropion, which X-linked ichthyosis lacks.
- Eczema craquelé
- Atopic dermatitis
- Allergic contact dermatitis or irritant contact dermatitis
Patient Information for X-linked ichthyosis in Child
OverviewX-linked ichthyosis is a relatively common genetic disorder affecting the skin in males. It is often seen at birth or shortly after. The affected skin can look "dirty," with brown scale that does not scrape or wash off. This is caused by a steroid deficiency and is not contagious.
Who’s At RiskX-linked diseases are inherited. Only boys will show signs of the disease, so boys with a family history of ichthyosis are most at risk.
Signs & SymptomsX-linked ichthyosis appears as brown scales on the skin, most often on the arms and legs, especially the armpits, elbows, and knees. The skin may appear dirty. Scales on the trunk and limbs may get worse with age, while head and neck scales may improve. It is rarely found on the palms of hands and soles of feet.
Self-Care GuidelinesThe following measures are recommended to reduce scaling:
- Moisturize several times a day and after bathing
- Use non-soap cleansers instead of soap
- Exfoliate with a textured sponge or loofah
- Use a humidifier, especially during winter months
When to Seek Medical CareBoys with a "dirty" looking face, neck, or scalp should be seen by a doctor.
Anywhere from 5% to 30% of patients with X-linked ichthyosis also have cryptorchidism, a term used when testicles don't fall into the scrotum before birth. If your baby with X-linked ichthyosis also has undescended testicles, please tell your pediatrician.
TreatmentsIchthyosis is a lifelong condition. Treatment will help, but it will not get rid of the scales entirely. Your doctor might prescribe a topical agent that contains one of the following:
- Alpha hydroxy acid
- Salicylic acid
X-linked ichthyosis in Child