When A Patient Has Increased Thickening Of The Skin And Increased Discoloration
One would make the diagnosis on clinical distribution, associated features and the presence of the condition in the family history. The majority of these diseases are present at birth or early in life. It is not unusual that patients may not have any skin changes until they are much older. If a patient has late onset hyperkeratosis, the differential must include the following conditions: hyperkeratotic eczema, palmoplantar psoriasis, acquired punctuate keratoses, arsenical keratoses and chronic tinea pedis.8
Hyperkeratotic eczema is focal and highly pruritic. Steroidal agents control the condition.
In regard to palmoplantar psoriasis, there is a silvery scale to the presentation. This often occurs in association with nail/joint involvement and lesions at other skin sites.
Acquired punctuate keratoses are sometimes associated with malignancy.
With chronic tinea pedis, there is extensive hyperkeratosis that resolves completely with antifungal therapy.
A Guide To Common Complications With Keratodermas
Pain. In regard to keratodermas, patients have more pain with punctuate keratoderma on weightbearing areas.
Difficulty in walking. The thickening of the plantar epidermis produces a stiffness that blunts sensation and makes movements more difficult.
Secondary infections (particularly tinea pedis and pitted keratolysis). The inflammatory response due to the infection may exacerbate the skin thickening. The use of systemic antifungal agents may help to decrease the thickness.
There may also be psychological implications of having a condition that others see as something different.
What You Should Know About Treatment
Unfortunately, the treatment of palmoplantar keratodermas, a lifelong condition, has always been less than adequate. When it comes to these genodermatoses, one can treat the conditions but not necessarily resolve them.
The first-line treatment has been debridement and the use of topical keratolytic agents (alpha-hydroxy acids such as lactic acid, glycolic acid and urea–based emollients). These agents do not totally resolve the condition but may help in selected individuals. Antifungal agents, both topical and oral, are reportedly useful for secondary infections of the hyperkerartotic condition.14
Physicians can utilize systemic retinoids to treat severe and diffuse forms of palmoplantar keratodermas in order to normalize the hyperkeratotic skin. Retinoids are natural and synthetic, and have biological activities that resemble those of vitamin A. They affect cell growth and differentiation, as well as cellular adhesiveness. They also are anti-inflammatory and can affect sebaceous glands.
There are three main types of oral retinoids. They include: isotretinoin (Accutane, Roche Pharmaceuticals), which is formally indicated for severe recalcitrant nodular acne; acitretin (Soriatane, Stiefel), which is indicated for severe psoriasis; and bexarotene (Targretin, Eisai), which is indicated for cutaneous manifestations of T-cell lymphoma.15 Physicians use these medications off-label to treat palmoplantar keratodermas so referral to other specialists may be warranted.
Systemic retinoids are not recommended for female patients with childbearing potential because of the long-term treatment approach and their slow elimination from the body. Complications such as periosteal hyperostosis may occur and teratogenesis is the most serious side effect.15
The more common side effects include dryness of skin and mucous membranes, reduced stratum corneum thickness and altered skin barrier function. Systemic retinoids will usually cause xerosis of the skin with pruritus and peeling, and sometimes skin fissuring.
In other patients, systemic retinoids may cause nail thinning and paronychia. Continued use of systemic retinoids may cause bone pain and idiopathic skeletal hyperostosis with calcification of tendons and ligaments.15
Dr. Morse is the President of the American Society of Podiatric Dermatology. He is a Fellow of the American College of Foot and Ankle Surgeons, and the American College of Foot and Ankle Orthopedics and Medicine. Dr. Morse is board certified in foot surgery.