Related articles: Ichthyosis
Definition
Ichthyosis is a group of diseases characterized by a defect in the process of formation and detachment (skin desquamation) of cells from the stratum corneum (ie the most superficial layer of the epidermis). Therefore, the skin is dry, rough, covered with scales and with a strong tendency to skin exfoliation.
Many ichthyosis are hereditary, others appear in isolated form. In some cases, ichthyosis may be an initial symptom of some systemic diseases, including leprosy, hypothyroidism, lymphoma and AIDS.
Most common symptoms and signs *
- Ataxia
- Muscular atrophy and paralysis
- Keratosis
- Keratosis pilare
- cryptorchidism
- Decreased sweating
- Ectropion
- Erythema
- Dandruff
- Hearing loss
- lagophthalmos
- Corneal opacity
- Dry skin
- itch
- Mental delay
- Scales on the skin
- Coarse and opaque nails
Further indications
The ichthyosis has variable clinical manifestations: from generalized dry skin to the presence of greyish scales and disfiguring lamellae. The desquamation can be fine and localized, or thick and widespread. Sometimes, it can be associated with variable skin inflammation.
Vulgar ichthyosis (non-congenital form) is manifested by thin, medium-sized scales on the back and on the extensor surfaces of the limbs; often, it is associated with atopic dermatitis and keratosis pilare.
X-linked ichthyosis is present from birth or from the first months of life, with large and dark scales mainly located around the neck and trunk. The disease affects only male subjects (recessive transmission is linked to the X chromosome) and can be associated with cryptorchidism and corneal opacity.
The lamellar ichthyosis also manifests itself at birth, with the characteristic "baby collodion", that is a glossy membrane that envelops the newborn determining ectropion (eyelid eversion) and anomalies of the auricular and nasal cartilages. Over time, the collodion gives way to large and coarse scales, distributed over most of the body, and to palmo-plantar thickening.
Syndromic ichthyosis has very variable skin involvement and systemic symptoms. Examples are Refsum's disease, which involves ataxia, polyneuritis and deafness, and Sjögren-Larsson syndrome associated with muscle paralysis and mental retardation.
Possible complications of ichthyosis include skin infections, sepsis and multi-organ failure.
The diagnosis is clinical and supported by diagnostic investigations, such as skin biopsy. The treatment is symptomatic and includes the use of emollients, moisturizers, creams with keratolytic action and, sometimes, of oral retinoids (such as acitretin and etretinate).
