Hand and foot dermatitis is a dermatitis affecting the hands and/or feet. It can be due to a contact dermatitis (allergic or irritant) or atopic dermatitis. Manifestations are erythema, scaling, and skin thickening. A unique feature of hand and foot dermatitis is that it commonly first manifests with tiny vesicles and is then called dyshidrotic dermatitis (although still hand and foot dermatitis). Diagnosis is clinical. Treatment depends on the cause and may include topical medications, phototherapy, and sometimes systemic immunosuppressants.
(See also Definition of Dermatitis.)
Pathophysiology of Hand and Foot Dermatitis
A hallmark histologic feature of dermatitis is edema between epidermal keratinocytes (spongiosis). When enough edema accumulates, cell-cell adhesions (desmosomes) rupture, forming microvesicles. The microvesicles become visible macroscopically only after they enlarge. In areas other than the hands and feet, these vesicles typically rupture quickly and are not noticed. However, on the hands and feet, because of their thicker stratum corneum, vesicles tend to persist longer and become visible. Visibility of these vesicles indicates dyshidrotic dermatitis (a misnomer because it has nothing to do with sweating or abnormal sweat glands).
The most severe form of dyshidrotic dermatitis, pompholyx, is characterized by coalescence of vesicles, forming larger bullae. Pompholyx is called cheiropompholyx when on the hands, podopompholyx when on the feet, and cheiropodopompholyx when on both hands and feet.
Symptoms and Signs of Hand and Foot Dermatitis
Erythema, scaling, and skin thickening may progress to pruritic vesicles or bullae on the palms, sides of the fingers, or soles (called dyshidrotic dermatitis), which can rupture, resulting in erosions and crusting. The vesicles may be the first symptom noticed. Depending on the etiology and exposures, symptoms can be intermittent.
Frequent or prolonged water contact (eg, frequent handwashing, work involving water or wet substances), particularly with detergents, is a common trigger, particularly in patients with atopy.
Diagnosis of Hand and Foot Dermatitis
Clinical evaluation
Diagnosis of hand and foot dermatitis can usually be inferred from location and appearance of the skin lesions.
Differential diagnosis of hand and foot dermatitis includes
Fungal infection
Palmoplantar psoriasis
Fungal infections, which have a similar skin inflammatory reaction, also cause pruritus, erythema, and scaling. Vesicles and blisters may become apparent (bullous tinea), typically visible only on the hands and feet, as with hand and foot dermatitis. The most discriminating differentiating feature, when present, is the characteristic annular shape of the fungal infection due to the centrifugal growth of dermatophytes in the skin.
Palmoplantar psoriasis may also be difficult to differentiate from hand and foot dermatitis. Features of palmoplantar psoriasis that can help in differentiation include erythematous and scaly plaques that are very sharply demarcated, sterile pustules, and other signs of psoriasis, such as psoriatic nail changes and psoriatic plaques elsewhere. Also, vesicles are possible with hand and foot dermatitis but are not a feature of palmoplantar psoriasis. However, vesicles and pustules can both be visible, for example:
When dyshidrotic dermatitis and palmoplantar psoriasis coexist
When vesicles in dyshidrotic dermatitis become superinfected
When patients with palmoplantar psoriasis become sensitized (eg, to topical corticosteroids) and develop an allergic contact dermatitis
When palmoplantar psoriasis is triggered (koebnerized) by an allergic contact reaction
Many disorders other than dermatitis can affect the hands and feet. Among these are
Fungal infections (eg, tinea manuum, tinea pedis, cutaneous yeast infections)
Viral infections (eg, herpetic whitlow, warts)
Bacterial infections (eg, impetigo, atypical mycobacterial infections)
Parasitic infections (eg, scabies, cutaneous larva migrans)
Hereditary epidermolysis bullosa (many different subtypes)
Keratolysis exfoliativa (lamellar dyshidrosis)
Hand-foot syndrome
Keratolysis exfoliativa (also known as lamellar dyshidrosis or dyshidrosis lamellosa sicca) is not an inflammation of the skin (and thus not a dermatitis). It affects the hands and feet and is characterized by annular erythema over the volar aspects of the hands and feet with air-filled blisters, possibly followed by peeling. Small annular collarettes of white scale may affect the palms (less often the soles) but spare the dorsal hands and feet. No fluid-filled blisters are present. Keratolysis exfoliativa may be aggravated by warm weather, hyperhidrosis, friction, and water contact.
Hand-foot syndrome
Treatment of Hand and Foot Dermatitis
Treatment of the cause when possible
Supportive measures
Topical medications and phototherapy
For severe disease, sometimes systemic corticosteroids or immunosuppressants
Treatment should be directed at the cause when possible.
Patients should avoid contact allergens as well as skin irritants, particularly frequent or prolonged contact with water and detergents.
Topical corticosteroids can be used, with the potency based on dermatitis severity. Antihistamines can help control pruritus.
Phototherapy with narrowband ultraviolet B (UVB) or with soak PUVA (in which patients soak their hands and/or feet in a psoralen solution before exposure to UVA) can help.
