Palmoplantar keratoderma

Management Strategy

PPK may be localized to the hands and feet or develop as part of a more generalized skin disorder. It is important when making a diagnosis to establish its morphology and the presence of any associated ectodermal disease at sites other than the palms and soles. Biopsy may be necessary to distinguish between some hereditary forms of PPK. PPK can be associated with infections (dermatophytes, human papillomavirus, HIV, syphilis, and scabies), drugs (arsenic exposure), and internal malignancy (paraneoplastic phenomenon) or may be a cutaneous manifestation of systemic disease (myxedema, diabetes mellitus). Hyperkeratosis of the palms and soles can also be a feature of eczema, psoriasis, and cutaneous T-cell lymphoma.

Treatment of PPK is challenging. Most therapeutic options produce only short-term improvement and are frequently complicated by unwanted adverse effects. Treatment options range from simple measures such as saltwater soaks with physical paring of the skin and use of topical keratolytics, through to systemic retinoids and reconstructive surgery with total excision of the hyperkeratotic skin followed by grafting.

In patients with limited disease, topical keratolytics containing salicylic acid, lactic acid, or urea in a suitable emollient base may be tried. Examples include 5–10% salicylic acid, 20–70% propylene glycol, or 10% lactic acid in aqueous cream or a combination therapy using 10% urea and 5% lactic acid in aqueous cream to be applied twice daily. These formulations can be made up on an individual basis or the closest proprietary product prescribed. The efficacy of these agents may be increased by occlusion at night.

Simple antiseptic soaks can prove helpful in reducing secondary dermatophyte and bacterial infections, which contribute to malodor affecting a significant number of PPK patients, as well as signs of skin maceration and fissuring.

Topical retinoids such as tretinoin (0.01% gel and 0.1% cream) may also be tried; treatment is, however, often limited by skin irritation. Potent topical corticosteroids , such as clobetasol propionate 0.05%, with or without keratolytics, are occasionally of value in the management of inflammatory PPK. 5-Fluorouracil 5% has produced dramatic results in spiny keratoderma, but its use in other keratodermas has not been evaluated.

The efficacy of the oral retinoids in keratoderma is well established. Good responses have been seen in mal de Meleda, Papillon–Lefèvre syndrome, and erythrokeratoderma variabilis. In some types of PPKs, particularly epidermolytic forms, hyperesthesia may limit the usefulness or practicality of treatment with retinoids. The potential risk of bone toxicity should also be assessed in patients on long-term therapy, although the risks are small. Periodic radiologic bone monitoring and, when possible, prescription of pulsed (intermittent) therapy are recommended. The optimal dosage of oral acitretin is 25–35 mg daily in adults or 0.6 mg/kg daily in children, which may be adjusted after 4 weeks of therapy. Oral isotretinoin 0.5 mg/kg is a less effective option. Oral alitretinoin 30 mg/day is a further option with mixed clinical response.

Psoralen plus UVA (PUVA) therapy or re-PUVA (a synergistic combination of oral retinoids and PUVA) may be effective in PPK secondary to psoriasis or eczema. In oculocutaneous tyrosinemia (an autosomal recessive condition characterized by focal palmoplantar keratosis, corneal ulceration, and mental retardation), dietary restriction of phenylalanine and tyrosine has led to resolution of PPK. Oral administration of 1α,25-dihydroxyvitamin D ₃ and topical calcipotriol ointment has been reported to be effective.

Regular podiatry, careful selection of footwear, and treatment of secondary fungal infections are integral parts of management of all PPK. Regular intermittent use of terbinafine cream and other topical antifungals can reduce skin maceration and improve comfort. Surgical or laser dermabrasion is an option for some patients, with potential amelioration of symptoms and improved penetration of topical agents.

For severe refractory PPK excision and skin grafting may be considered. Excision should remove hyperkeratotic skin, including dermis, epidermis, and subcutis, to prevent any risk of recurrence. Establishing the genetic cause of various inherited PPKs has so far not translated into therapeutic advances.