Ichthyosis is a common hereditary skin keratosis, formerly known as ichthyosis, referred to as "ichthyosis" in Chinese medicine. It primarily manifests as dry, rough skin on the extensor surfaces of the limbs or the trunk, accompanied by rhomboid or polygonal scales resembling fish scales or snake skin. Depending on the inheritance pattern, it can be classified into autosomal dominant ichthyosis vulgaris, X-linked ichthyosis vulgaris, congenital ichthyosiform erythroderma, and lamellar ichthyosis.

bubble_chart Clinical Manifestations

According to symptoms and signs, it can be divided into four types:

1. Dominant ichthyosis vulgaris
   1. Onset occurs between 3 months and 5 years after birth;
   2. Dry skin covered with gray-white to light brown water calptrop base peel-shaped or polygonal scales, with edges lifted and the center tightly adhered to the skin;
   3. Mainly distributed on the extensor surfaces of the limbs and the back;
2. X-linked ichthyosis vulgaris
   1. Onset occurs within 3 months after birth, affecting only males;
   2. Dry and thickened skin covered with large, dark brown scales, worse in winter and milder in summer. The condition does not improve with age and may even worsen;
   3. Skin lesions are distributed all over the body, most severely affecting the head, face, sides, front of the ears, and neck. The flexural areas are often involved.
3. Congenital ichthyosiform erythroderma
   1. At birth, the entire body is covered with armor-like multilayered scales, which shed to reveal rough, moist surfaces, and may present with flaccid blisters;
   2. In severe cases, the hands and feet may appear claw-like;
   3. Autosomal dominant inheritance.
4. Lamellar ichthyosis
   1. At birth, the infant is tightly wrapped in a widespread collodion-like membrane, which sheds after a few days, leaving the skin extensively reddened with large polygonal scales, adherent in the center and free at the edges;
   2. Hyperkeratosis of the palms and soles, with overgrowth of nails and hair;
   3. Two-thirds of patients exhibit ectropion.

bubble_chart Diagnosis

1. Genetic diseases;
2. cutaneous manifestations of type IV;
3. histopathological changes
   1. Dominant hereditary ichthyosis: grade II epidermal hyperkeratosis, accompanied by thinning or disappearance of the granular layer;
   2. X-linked ichthyosis vulgaris: hyperkeratosis, with a normal or slightly thickened granular layer;
   3. Epidermolytic hyperkeratosis ichthyosis: hyperkeratosis, epidermal cell lysis, and granular degeneration.

bubble_chart Treatment Measures

Treatment Principles

1. There is currently no cure, and the goal of treatment is to alleviate symptoms, increase stratum corneum hydration, and promote normal keratinization;
2. Systemic therapy may include vitamin A, 13-cis retinoic acid, etretinate, or methotrexate;
3. Topical treatments can enhance stratum corneum hydration and remove excessive keratinization, such as urea cream, retinoic acid, salicylic acid, etc.;
4. For infections, topical antibiotics ointment may be used.

1. Mild ichthyosis can be treated with oral vitamin A, topical urea cream, salicylic acid, and retinoic acid preparations;
2. Topical antibiotics ointment can eliminate infections or reduce odor;
3. Severe ichthyosis may be treated with etretinate, 13-cis retinoic acid, or methotrexate.

bubble_chart Cure Criteria

1. Cured: More than 90% of skin lesions have subsided;
2. Improved: More than 50% of skin lesions have subsided;
3. Not cured: Less than 30% of skin lesions have subsided.