Medical Care
Systemic therapy
Oral retinoids display an impressive antikeratinizing action in ichthyosiform dermatoses. Etretinate (1 mg/kg/d) and isotretinoin (2 mg/kg/d) have been shown to reduce scaling, discomfort, and disfigurement. However, when these drugs are discontinued, the ichthyotic skin recurs, thereby necessitating long-term use. Similarly, liarozole (150 mg bid), an imidazole derivative, inhibits the cytochrome P450-dependent 4-hydroxylation of retinoic acid, resulting in increased tissue levels of retinoic acid and a reduction in epidermal proliferation and scaling.
Patients with epidermolytic hyperkeratosis may develop chronic bacterial infections of the skin necessitating long-term antibiotic therapy.
Patients with Sjögren-Larsson syndrome have a deficiency of fatty aldehyde dehydrogenase (FALDH). Data suggest that bezafibrate, a hypolipidemic drug, induces the activity of FALDH in patients with some residual enzyme activity.
Ocular therapy
The primary aim of eye care in both adults and children with ichthyosis is to maintain moisture, integrity, and clarity of the cornea. When ichthyosis involves the eye or eyelids, there is a high risk of the cornea becoming dry and developing an epithelial defect that may lead to an infection of the cornea. Corneal infections may result in a scar that reduces the clarity of the eye or, at worst, perforation of the cornea.
In chronic ocular surface disorders associated with ichthyosis, nonpreserved artificial tears (carboxymethylcellulose sodium 0.5-1.0%) and ointment (white petrolatum 56.8%, mineral oil 41.5%) are preferred to prevent complications from dryness and exposure.
Preservative-free lubricants may be used as often as needed while decreasing the incidence of preservative-related allergies.
In cases where poor corneal epithelial adhesion is present, bandage contact lenses and temporary collagen shields may decrease symptoms and promote surface healing.
Topical therapy
Topical cyclosporine A 2% given 3 times daily has been shown to be beneficial in the treatment of deep stromal keratitis associated with KID syndrome.
To prevent cicatricial ectropion in lamellar ichthyosis, a humidified atmosphere combined with the use of topical moisturizing agents is beneficial. Petrolatum ointment and 10% urea cream applied to the eyelid skin several times daily helps to prevent skin contracture. Salicylic acid 2% and retinoic acid 0.1% ointments also are effective, but local irritation may limit their frequency of use. In the hyperproliferative variants of ichthyosis, calcipotriene ointment has been shown to be beneficial. However, the use of calcipotriene in treating congenital hyperproliferative disorders is limited by the theoretical risk of hypercalcemia from absorption of the drug from the skin.
Pimecrolimus 1% (Elidel) an immunomodulating agent used in the treatment of atopic dermatitis, has been shown to be effective in patients with Netherton syndrome. The immunomodulating effects are similar to tacrolimus but without evidence of lipophilic adverse effects.
Surgical Care
When cicatricial ectropion develops in patients with lamellar ichthyosis despite room humidification and vigorous skin lubrication, the danger of corneal breakdown and perforation is noted. Full-thickness skin grafts from the forearm, postauricular, and groin areas may be used to successfully repair the abnormalities. [7] In addition, Apligraf (Organogenesis Inc, Canton, Mass), a human skin equivalent, may facilitate the repair of cicatricial ectropion in severe cases when autologous donor graft tissue is not available. A concomitant medial and/or lateral lid tarsorrhaphy is recommended in severe cases. The incidence of ectropion recurrence may be decreased if surgery can be postponed until suitable nonscaly patches of skin can be clearly identified to serve as graft donor sites.
For a persistent corneal epithelial defect, an amniotic membrane transplantation may be necessary to promote epithelial wound healing.
For diffuse limbal stem cell deficiency, keratolimbal allografting with chronic systemic immunosuppression may be necessary, although the success rate has been poor.
Consultations
Because ichthyosis is primarily a skin disorder, periodic evaluation by a dermatologist is recommended.
The ophthalmologist may be helpful in the treatment of ocular manifestations and in the identification of the specific type of ichthyosis, particularly, lamellar and X-linked forms.
Diet
In patients with Refsum disease (ichthyosis and pigmentary retinopathy), chlorophyll in the diet should be excluded (ie, green vegetables [phytanic acid], animal fat [phytol]). Because rapid weight loss mobilizes tissue phytanic acid, this should be avoided.
Complications
Because skeletal hyperostosis and arthralgia may occur with long-term oral etretinate and isotretinoin use, this form of treatment is reserved only for those patients with very severe scaling and cosmetic deformity. The clinical adverse effects of oral liarozole are reminiscent of those with oral retinoids; therefore, precaution is warranted with long-term use. Topical dermatologic retinoid preparations are irritating to the conjunctival fornices; therefore, it should not be applied directly to the eye. Topical tazarotene 0.1% gel may be an effective alternative to oral retinoids, with a decreased risk of systemic complications.
In the hyperproliferative variants of ichthyosis, topical calcipotriene ointment has been shown to be beneficial. However, the use of calcipotriene in treating congenital hyperproliferative disorders is limited by the theoretical risk for hypercalcemia from absorption of the drug from the skin.
Further Outpatient Care
The mainstay of ichthyosis therapy includes removal of surface scales, and application of a water barrier.
In disabling cases, oral retinoids may reduce cosmetic disfigurement, depression, and social isolation.
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This direct illumination slit lamp photograph discloses a reticular central corneal haze that is seen bilaterally. Visual acuity is 20/20 in both eyes. The patient's chief complaint is photophobia and dry scaly skin.
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This slit beam illumination photograph of the cornea localizes the corneal opacity to the posterior stroma and the pre-Descemet membrane region. This type of corneal opacity is commonly present in X-linked recessive ichthyosis.
