Hands have structures with many unique structural and functional features. As such, they are prone to developing specific dermatologic diseases. Structurally, the palms have a thick keratin layer, a high concentration of sweat glands, Meissner's corpuscles, and other mechanoreceptors. Functionally, we use our hands to explore the world. Therefore, hands are subject to physical injury. Hands are often the first body part to come into contact with objects and substances in our environment. As a result, they are frequently the site of exposure to allergens, irritants, and infectious agents. This concept is central to the transmission of pathogens and development of certain dermatologic conditions such as contact dermatitis. Given their distal location, the neurovascular supply of hands (particularly the digits) can also predispose to neuropathies and ischemic insults. The dorsal hands tend to get more sun exposure than centrally located anatomical structures thereby subjecting them to photodermatoses and actinic damage. Hands may also manifest cutaneous signs of internal disease.
Skin diseases involving the hands can be broadly placed into the following categories starting with the most common diseases (Table 38-1):
Table 38-1.Skin diseases of the hands. ||Download (.pdf) Table 38-1. Skin diseases of the hands.
Allergic contact dermatitis (ACD)
F > M.
Age: Any age, more common in adults due to increased topical product usage.
Itchy rash, sometimes with blisters and painful fissures. Onset is hours to days after contact with allergen.
Geometric or linear configuration as well as a sharply demarcated distribution are clues to an external cause.
Acute: Pink to red, edematous papules and plaques with vesiculation.
Chronic: Xerosis, fissuring, hyperpigmentation, and lichenification at sites of direct contact with allergen.
Distribution will be a clue to culprit allergen.
Distinguish from other types of dermatitis due to a sharply demarcated distribution and geometric/linear configuration. Can be very difficult to differentiate from irritant contact dermatitis and atopic hand dermatitis, without patch testing. Distinguish from atopic dermatitis due to history of atopy and additional classic areas of involvement of atopic dermatitis.
(see Chapter 8).
Irritant contact dermatitis (ICD)
F > M.
Age: More common in adults.
Pruritic, burning, or painful.
Variable onset depending on frequency of exposure and strength of irritant (e.g., cleansers, soaps, detergents, repetitive friction, wet work, or frequent hand washing).
Patients with atopic dermatitis are at increased risk.
Well-demarcated with a "glazed" appearance. Erythema, fissures, blistering and scaling, usually in finger web spaces, or dorsum of hands.
Distinguished from allergic contact dermatitis by patch testing. ICD more common than ACD. Distinguish from atopic dermatitis due to history of atopy and classic areas of involvement of atopic dermatitis.
(see Chapter 8).
Atopic hand ...