Ichthyosis
Introduction
Introduction to ichthyosis Ichthyosis is commonly known as (snake skin), 70% is genetic (genetic disease), more than the incidence of children, the hair parts of the limbs are on the back, the skin is dry and rough, the edges of the dander are slightly tilted, resembling snake skin, or sweat pores. There are clogging of particles, no hair can be found, and the skin is grayish-brown scaly and deep and heavy. It spreads with the whole body with age, and the disease is characterized by heavy winter and light summer. Ichthyosis is a common hereditary skin keratoderma, which is called snakeskin. basic knowledge The proportion of illness: 0.003%-0.008% Susceptible people: more common in children Mode of infection: non-infectious Complications: nystagmus, polyneuritis, ataxia
Cause
Cause of ichthyosis
Epidermolytic keratosis ichthyosis (15%):
It is an autosomal dominant genetic disease. The pathogenic gene is associated with keratin 1 (K1) and keratin 10 (K10) gene mutations, leading to defects in the synthesis or degradation of keratin, affecting the normal arrangement and function of tension microfilaments in basal keratinocytes, resulting in keratinization. Abnormalities and epidermis release.
Lamellar ichthyosis (15%):
Autosomal recessive inheritance. The gene localizes multiple sites, including 2q33-35, 19p12-q12, localization to the 14q11TGM1 gene mutation, deletion or insertion, to cell adhesion and cell envelope protein cross-linking defects.
Ichthyosis vulgaris (20%):
It is an autosomal dominant genetic disease with incomplete penetrance. It is currently thought to be caused by instability of mRNA and defective post-transcriptional control mechanisms.
Sexual recessive ichthyosis (15%):
Invisible inheritance for X chromosome linkage. The steroid sulfatase gene (STS) is deleted or mutated, causing the accumulation of cholesterol sulfate, and the stratum corneum cells are tightly bound and cannot be properly detached to form scales.
Congenital non-bullous ichthyosis-like erythroderma (15%):
It is autosomal recessive, and is caused by mutation of multiple genes such as lipoxygenase 12 (R) (ALOX12B) gene and lipid oxidase 3 (ALOXE3) gene.
Roundabout linear ichthyosis (10%):
An autosomal recessive disorder caused by a mutation in the serine protease inhibitor Kazal5 (SPINK5) gene on chromosome 5p32.
Prevention
Ichthyosis prevention
This problem really needs to be highly valued: if the disease is married before it is cured, it is likely to be inherited to the next generation. Only by curing the disease can you get married, and you should strengthen your exercise. You should drink more boiled water for your life. Vitamin A.
For hereditary ichthyosis, the genetic probability of offspring will be greatly improved, and marriage can be achieved, but fertility is not suitable.
Complication
Ichthyosis complications Complications, nystagmus, polyneuritis, ataxia
The ichthyosis-related syndromes are mostly autosomal recessive inheritance. In addition to involving multiple organs and/or tissues, they are accompanied by different degrees of ichthyosis-like damage. They are also an important component of these syndromes, and the clinical symptoms are different. The IAS may be a manifestation of gene pleiotropic effects. The main syndromes associated with ichthyosis are:
1 ichthyosis, spasticity, mental retardation syndrome
For a rare syndrome consisting of congenital ichthyosis, spastic limb paralysis and triad disorder, almost all patients have extensive ichthyosis damage at birth, and about half have varying degrees of erythroderma, red skin. The disease gradually relieves with age, disappears after adulthood, and there are three types of ichthyosis that end in life: the folds are often translucent black or black and yellow, and the dermatoglyphic lesions are deepened; the limbs and lower abdomen are The lamellar ichthyosis damage; other damage is characterized by a large number of thin dry scales, the same patient often has three kinds of skin lesions, common valgus valgus, individual patients with dry hair, slender, dull.
Most patients develop neurological lesions within 4 to 30 months after birth, mainly mental retardation, spastic quadriplegia or paraplegia, progressive exacerbation of lower extremity spasm, at least until puberty remission or stop progression, most patients The upper limbs have similar lesions, but they are lighter. Most patients have mental retardation and do not increase with age.
2 ichthyosis pygmy mental disorder syndrome:
This is a syndrome consisting of ichthyosis-like erythroderma, gnome, mental disorder and spastic sputum. In the case record: 3 children were found among 5 children of a close relative and married couple. The proband was 18 The old woman, 137cm tall, has erythroderma on the face at birth, a little bullae on the back of the foot, diffuse redness in the body for several months, and the skin is atrophied and thinned like a parchment at the back of the foot. , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,
3 intelligent disorder epilepsy ichthyosis syndrome:
Infancy, mainly caused by mild ichthyosis-like erythroderma, mental disorders and epilepsy triad, but some patients also have genital hypoplasia, gnomes and other symptoms, poor intelligence, can not take care of themselves, epilepsy is mostly large Onset, the disease may be caused by autosomal recessive inheritance, but sexual chain inheritance cannot be ruled out.
4 ichthyosis hepatosplenomegaly ataxia syndrome:
Dykes and Harper (1979-1980) first reported the disease. The proband was a 69-year-old male with dry skin disease in children. Consonant dysfunction and gait instability after progressive 62 years of age, dry skin disease The most obvious limb extension, palmprint is deep, hepatosplenomegaly, hard but liver function is normal, neurological examination has senile dementia, limb and trunk movement ataxia, dysarthria, difficulty gazing upwards.
5 hair shaft abnormal intelligence disorder ichthyosis syndrome:
The disease has ichthyosis-like erythroderma, brittle hair caused by abnormal dryness, mental retardation, reduced fertility and short stature, so as to find that the parents in such patients have no disease, both men and women, so It is believed that this disease is caused by multiple autosomal recessive inheritance.
6 ichthyosis polyneuritis ataxia syndrome:
For a rare autosomal recessive hereditary disease, the main symptoms and signs of patients are due to nervous system involvement, infancy, ataxia manifested as gait instability, intentional tremor and nystagmus, and limb weakness, far End muscle weakness, even muscle atrophy, deep emission weakened or disappeared, in addition to neurological deafness, olfactory loss, most patients have mild ichthyosis lesions, patients died of acute polyneuropathy, renal failure or heart Depletion.
7 ichthyosis, bamboo-like hair allergy syndrome:
The disease is mainly composed of congenital ichthyosis-like erythroderma, bamboo hair and genetic allergy. It is rare. Most of the patients are women. There are diffuse erythroderma and desquamation at birth or shortly after birth, but red skin. The degree, extent and duration are different. The clinical manifestations of ichthyosis are the same as those of localized linear ichthyosis. The hair is sparse and soft, dull, dry and abnormal. It is characterized by intussional brittle hair, which is called bamboo. Hair.
Symptom
Symptoms of ichthyosis Common symptoms Layered fish scales Skin edge up Skin allergies Epidermis keratinized erythema Scales Large amount of skin desquamation Limb keratinization
Mainly manifested as dry or rough skin on the extremities or trunk of the extremities, accompanied by rhomboid or polygonal scales, the appearance of which is like fish scales or snakeskin, severe skin cleft palate, stiff skin, leading to sparse sweat and abnormal perspiration, resulting in internal body Unbalanced water and liquid metabolism affects the endocrine system.
Histopathological changes:
(1) dominant hereditary ichthyosis: moderate hyperkeratosis of the epidermis with thinning or disappearance of the granular layer;
(2) Orthotopic ichthyosis: excessive keratinization, normal or slightly thick granular layer;
(3) Epidermolytic hyperkeratosis ichthyosis: hyperkeratosis, epidermal cell release, particle degeneration.
Examine
Ichthyosis examination
1. Routine examination: Whether the skin on the extremities or trunk of the extremities is dry and rough, or accompanied by rhomboid or polygonal scales; whether the appearance is like fish scales or snakeskin, whether the skin is cleft or not, and whether the epidermis is stiff or not.
2, need to carry out pathological examination of skin lesions and dermatological examination.
Diagnosis
Diagnostic identification of ichthyosis
Diagnostic basis for ichthyosis:
1. Have a family history;
2. Skin lesion performance;
3. Histopathological changes
(1) The dominant epidemic ichthyosis is moderately hyperkeratotic with thinning or disappearance of the granular layer;
(2) Orthotopic ichthyosis keratosis, normal or slightly thick granular layer;
(3) Epidermolytic hyperkeratosis ichthyosis epidermal keratosis or granule degeneration.
Identification of four major types of ichthyosis:
1, ichthyosis vulgaris: mainly in the dry limbs of the limbs and the trunk of the dry brown diamond, or polygonal scaly, the upper arm and thigh extension often have obvious follicular keratotic papules, palm toe involvement, high incidence, Its keratinized scaly is caused by several layers of keratinocytes not falling off, more than a few months after birth, the heaviest around 5 years old, the symptoms may be alleviated after puberty, but the condition is worse with age and treatment.
2, sexually linked hidden ichthyosis: can occur after birth or infants, skin lesions are large and significant, yellow-brown or dirty black large scale fish scale, dry and rough skin, often throughout the body, armpits, and elbow fossa Can be affected; abdomen, the back is particularly heavy, such as facial involvement, it is limited to the front of the ear and the side of the face, generally does not occur follicular keratosis, the skin at the palm of the hand is normal, the skin lesions do not reduce with age, and sometimes increase weight.
3, epidermis loosening hyperkeratosis ichthyosis, also known as bullous congenital ichthyosis-like erythroderma: an autosomal dominant genetic disease with high distortion rate, clinically rare, after birth or several months after birth, can There are generalized and limited lesions. When the generalized person is born, there is a thick layer of scales in the whole body. After birth, it will fall off, and there will be generalized flushing and scales. The scales will be removed and the erythema will gradually disappear. Thicker scaly scales can occur again. The limited nature of the situation can only have thicker scaly horny lobes in the flexor and wrinkle parts of the extremities.
4, lamellar ichthyosis: autosomal recessive inheritance, after the whole body is a wide layer of human cotton gelatinous membrane tightly wrapped, causing eyelids and lip eversion, the film peeled off after a few days, skin It has a wide diffuse flushing with grayish white or taupe polygons or diamond-shaped large scales. The center is fixed and the edges are free. It is often symmetrical in the whole body. The limbs are flexed, the elbow fossa, the armpits and the vulva are more obvious. Excessive keratinization, excessive growth of nails and hair, slow progression of the disease, can eventually survive, until the erythrodony can be reduced in adulthood, but the scales still exist.
