Epidermolytic hyperkeratosis

Epidermolytic Ichthyosis (EI)
Other names	Bullous epidermis ichthyosis
Specialty	Medical genetics

Epidermolytic ichthyosis (EI),^[a] is a severe form of dry scaly skin, that initially presents with redness, blisters, erosions, and peeling in a newborn baby.^[5][6] Hyperkeratosis typically develops several months later.^[6] Other symptoms include itch, painful fissures, strong body odor, and absence of sweat.^[6] Symptoms vary in severity and extent of skin involvement.^[5] The two main types are divided into one involving palms and soles and the other without.^[6]

EI is caused by a genetic mutation.^[6] The condition involves the clumping of keratin filaments.^[5][6]

The condition is rare, affecting around 1 in 200,000 to 300,000 babies.^[6]

EI is a severe form of dry scaly skin, that initially presents with redness, blisters, erosions, and peeling in a newborn baby.^[5][6] Hyperkeratosis typically develops several months later.^[6] Other symptoms include itch, painful fissures, body odor, and absence of sweat.^[6] Symptoms vary in severity and extent of skin involvement.^[5] Complications include infection and joint problems.^[6] Affected newborns are particularly at risk of dehydration, sepsis, and electrolyte imbalance.^[6]

The condition is mostly inherited in an autosomal dominant pattern.^[6] To a lesser extent, a recessive form exists.^[5] It is caused by genetic mutations in the genes encoding the proteins keratin 1 or keratin 10, resulting in disruption of the structure of the epidermis.^[6]

• Keratin 1 is associated with the variants affecting the palms and soles.^[6]
• Keratin 10 is associated with the variants in which these are unaffected.^[6]

Diagnosis is by its appearance, skin biopsy, and genetic testing.^[6]

The condition can be diagnosed via exam that reveals; generalized redness; thick, generally dark, scales that tend to form parallel rows of spines or ridges, especially near large joints; the skin is fragile and blisters easily following trauma; extent of blistering and amount of scale is variable.^{[citation needed]}

Treatment includes applying thick moisturisers.^[5] Other therapies include topical and oral retinoids.^[5] These include topical N-acetylcysteine, liarozole, and calcipotriol.^[6] Bacterial colonisation of skin may be reduced by use of antibacterial soaps, chlorhexidine, and dilute sodium hypochlorite baths.^[6]

Gene therapy is being studied for EI.^[7]

The condition is rare, affecting around 1 in 200,000 to 300,000 babies.^[6]

EI was first classified by its presence or absence in the palms and soles by DiGiovanna and Bale in 1994.^[6][8]

• Ichthyosis bullosa of Siemens
• Isotretinoin (Accutane)
• List of cutaneous conditions
• List of cutaneous conditions caused by mutations in keratins
• List of verrucous carcinoma subtypes
• Nonbullous ichthyosiform erythroderma