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 hand to interact with 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 the hands to neuropathies, ischemic insults, and vasculitides. 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 primarily involving the hands can be broadly categorized into inflammatory dermatoses, infections, connective tissue disorders, and photodermatoses (see Table 33-1). Widespread actinic keratoses on the hands are also included in this chapter because they are sometimes misdiagnosed as a "rash." The inflammatory dermatoses are most common and typically present with pruritic papules or plaques. The morphology of tinea manuum depends on its distribution, with annular plaques being more common on the dorsal hand and diffuse fine scale on the palm. Sunlight-induced dermatoses and connective tissue disorders present on the dorsal hands with pink papules and plaques.
Table 33-1.Differential diagnosis for diseases of the hands. ||Download (.pdf) Table 33-1. Differential diagnosis for diseases of the hands.
|Disease ||Epidemiology ||History ||Physical Examination |
|Irritant contact dermatitis || |
F > M
Atopics are at increased risk
Pruritic, burning, or painful
Variable onset depends on frequency of exposure and strength of irritant
Well-demarcated with a "glazed" appearance
Erythema, fissures, blistering, and scaling usually in finger web spaces or dorsum of hands (Figures 8-1, 8-2, 8-3)
|Allergic contact dermatitis || |
F > M
|Pruritic with onset hours to days after contact with allergen || |
Acute: papules and vesicles on an erythematous base (Figures 8-4 and 8-5)
Chronic: xerosis, fissuring, hyperpigmentation, and lichenification usually on the dorsum of hand and distal fingers (Figures 8-1, 8-2, 8-3)
|Atopic dermatitis || |
F > M
May be only manifestation of disease in adults
Pruritic and sometimes painful
Chronic course with exacerbations
Triggers: frequent hand washing or wet work
Usually worse in winter
Family history of atopy
|Presents with swelling, xerosis, fissuring, erythema, and lichenification on dorsum and palms (Figure 2-10) |
|Dyshidrotic dermatitis || |
F ≥ M
Age: young adults and atopics overrepresented
Chronic and ...