Epidermolytic hyperkeratosis

Template:Infobox medical condition (new) Epidermolytic ichthyosis (EI),Template:Efn is a severe form of dry scaly skin, that initially presents with redness, blisters, erosions, and peeling in a newborn baby.<ref name=Andrew2020>Template:Cite book</ref><ref name=Rice2023>Template:Cite journal</ref> Hyperkeratosis typically develops several months later.<ref name=Rice2023/> Other symptoms include itch, painful fissures, strong body odor, and absence of sweat.<ref name=Rice2023/> Symptoms vary in severity and extent of skin involvement.<ref name=Andrew2020/> The two main types are divided into one involving palms and soles and the other without.<ref name=Rice2023/>

EI is caused by a genetic mutation.<ref name=Rice2023/> The condition involves the clumping of keratin filaments.<ref name=Andrew2020/><ref name=Rice2023/>

The condition is rare, affecting around 1 in 200,000 to 300,000 babies.<ref name=Rice2023/>

Signs and symptoms

EI is a severe form of dry scaly skin, that initially presents with redness, blisters, erosions, and peeling in a newborn baby.<ref name=Andrew2020/><ref name=Rice2023>Template:Cite journal</ref> Hyperkeratosis typically develops several months later.<ref name=Rice2023/> Other symptoms include itch, painful fissures, body odor, and absence of sweat.<ref name=Rice2023/> Symptoms vary in severity and extent of skin involvement.<ref name=Andrew2020/> Complications include infection and joint problems.<ref name=Rice2023/> Affected newborns are particularly at risk of dehydration, sepsis, and electrolyte imbalance.<ref name=Rice2023/>

Cause and mechanism

The condition is mostly inherited in an autosomal dominant pattern.<ref name=Rice2023/> To a lesser extent, a recessive form exists.<ref name=Andrew2020/> 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.<ref name=Rice2023/>

• Keratin 1 is associated with the variants affecting the palms and soles.<ref name=Rice2023/>
• Keratin 10 is associated with the variants in which these are unaffected.<ref name=Rice2023/>

Diagnosis

Diagnosis is by its appearance, skin biopsy, and genetic testing.<ref name=Rice2023/>

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.Template:Citation needed

Treatment

Treatment includes applying thick moisturisers.<ref name=Andrew2020/> Other therapies include topical and oral retinoids.<ref name=Andrew2020/> These include topical N-acetylcysteine, liarozole, and calcipotriol.<ref name=Rice2023/> Bacterial colonisation of skin may be reduced by use of antibacterial soaps, chlorhexidine, and dilute sodium hypochlorite baths.<ref name=Rice2023/>

Research

Gene therapy is being studied for EI.<ref name=Joosten2022>Template:Cite journal</ref>

Epidemiology

The condition is rare, affecting around 1 in 200,000 to 300,000 babies.<ref name=Rice2023/>

History

EI was first classified by its presence or absence in the palms and soles by DiGiovanna and Bale in 1994.<ref name=Rice2023/><ref name="pmid8053700">Template:Cite journal</ref>

See also

• 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