Keratosis pilaris is not present, and the incidence of atopy is not increased. A diagnosis of X-linked ichthyosis is likely if the abdomen is more involved than the back, and if the ichthyosis extends down the entire dorsum of the leg. The condition may be confused with ichthyosis vulgaris but typically has darker scales and demonstrates dramatic clearing during the summer months. The elbow and knee flexures are relatively spared, as are the face and scalp the palms and soles are almost always spared. The sides of the neck are invariably involved, giving the child an unwashed look. Scales are dark, large, and prominent on the anterior neck, extensor surfaces of the extremities ( Fig. Cesarean birth is typical, with failure in progression of labor because of a placental sulfatase deficiency. This condition results from a deficiency of steroid sulfatase (arylsulfatase C) and occurs in 1 : 2000 to 1 : 5000 male births.
X-linked ichthyosis is transmitted only to males by heterozygous mothers as an X-linked recessive trait. James MD, in Andrews' Diseases of the Skin, 2020 X-Linked Ichthyosis
81,82 In a recent case of a female with severe ichthyosis and atopic eczema, both a steroid sulfatase deletion mutation and a frameshift mutation in the gene encoding filaggrin (a finding of ichthyosis vulgaris) were found.
#X LINKED ICHTHYOSIS FULL#
66 Full expression of the disease has only been reported in a few females. Its incidence is approximately 1 in 5000 to 6000 males, but, occasionally, female heterozygotes have mild scaling of the legs. The patient with recessive dystrophic epidermolysis bullosa had a partial deletion of the steroid sulfatase gene and a recessive point mutation in the COL7A1 gene. 77,78 Coexistence of X-linked ichthyosis with dominant 79 and recessive 80 dystrophic epidermolysis bullosa has been reported. 76 Male-pattern baldness does occur, despite earlier claims to the contrary. 75 Ichthyosis vulgaris and X-linked ichthyosis have been reported in the same family (see later). 74 An association with steroid-resistant nephrotic syndrome has been reported. 70 It has also been associated with the oculoauriculovertebral spectrum (Goldenhar syndrome OMIM 164210), 71 Leri–Weill dyschondrosteosis, 72 Crigler–Najjar syndrome 1, 73 and Nagashima-type palmoplantar keratosis. 70 Interestingly, X-linked ichthyosis and Kallmann's syndrome result from abnormalities in contiguous genes. 67 Other rare associations include congenital dislocation of the hip, 68 Poland's syndrome (unilateral absence of the pectoralis major muscle OMIM 173800), 69 and Kallmann's syndrome (hypogonadism, renal agenesis, anosmia, and synkinesis OMIM 308700). 63–66 Recent emphasis has been placed on the association of nonsyndromic X-linked ichthyosis with neurological disorders, including epilepsy and attention-deficit/hyperactivity disorder. 62 Corneal opacities and mental retardation may also occur in X-linked ichthyosis. The preauricular region is characteristically involved in this variant of ichthyosis in contrast, this site is usually spared in ichthyosis vulgaris. X-linked ichthyosis may involve the entire body in varying degree, although there is sparing of the palms and soles. It is characterized by large polygonal scales that are dirty brown in color and adherent. The X-linked form of ichthyosis (OMIM 308100 ), which is inherited as an X-linked recessive trait, is present at birth or develops in the first few months of life.
#X LINKED ICHTHYOSIS SKIN#
Patterson MD, FACP, FAAD, in Weedon's Skin Pathology, 2021 X-Linked Ichthyosis
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