Dyshidrotic eczema

Dyshidrotic eczema is also called "dyshidrosis" and "pompholyx". Dyshidrotic eczema accounts for 20-25% of cases of palmar eczema.

This form of eczema is a characteristic chronic relapsing eczematous dermatitis of unknown etiology. Dyshidrotic eczema is characterized by sudden rashes of usually intensely itchy, symmetrical vesicles on the palms, lateral surfaces of the fingers and/or soles.

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Causes of Dyshidrotic Eczema

Patients usually have a history of atopy (personal or family history of asthma, hay fever, or atopic eczema). Moderate to severe itching typically precedes an outbreak or relapse. Hyperhidrosis (excessive sweating) often accompanies or worsens the condition. The peak incidence in women is in the early 20s and in men in the mid-40s.

Symptoms of Dyshidrotic Eczema

Symptoms of dyshidrotic eczema are characterized by the appearance of vesicles 1-5 mm in diameter, which are monomorphic, deep-seated, croup-like lesions filled with clear fluid. Vesicles appear suddenly and symmetrically on the palms and lateral surfaces of the fingers or on the soles. Rings of scale and scaling replace the vesicles as the itching subsides. Depending on the phase of the disease, the clinician may observe only brown spots. When the acute process ends, the skin peels off and a red, cracked base with brown spots opens. The brown spots are the sites of former vesiculation. The vesicles resolve slowly over 1-3 weeks. This may be followed by chronic eczematous changes with erythema, scaling, and lichenification. Wave-like relapses with the appearance of symmetrically located vesicles may occur indefinitely often. For unknown reasons, chronic recurring rashes sometimes go away over time.

Differential diagnosis of dyshidrotic eczema

Pustular psoriasis of the palms and soles (the main complaint of patients is more often pain than itching). "Id" reaction (resulting from a distant source of fungal infection). Inflammatory fungal infection (positive KOH test for fungi). Acute allergic contact dermatitis. Bullous pemphigoid (may be hemorrhagic). Cutaneous T-cell lymphoma (rare).

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Treatment of Dyshidrotic Eczema

Treatment of dyshidrotic eczema begins with cool, wet compresses with either tap water or Burow's solution, followed by application of a moderate to high potency steroid cream (groups I or III). Prednisone 0.5-1 mg/kg/day is prescribed, tapering the dose over 1-2 weeks. Some relief may be provided by tacrolimus ointment (Protopic 0.1%), alternated with twice-daily application of a medium-strength topical corticosteroid (groups I-III) in several 3-4-week cycles. Corticosteroids should not be used repeatedly or to treat chronic disease. Systemic antihistamines may relieve itching. Topical psoralen on the palm plus ultraviolet A is an option for treating frequent, torpid rashes. Disulfiram (Antabuse 200 mg/day for 8 weeks) may help nickel-sensitive patients with dyshidrotic palmar eczema. If a distant fungal source is identified and the KOH test is positive, the fungal lesion should be treated with an aggressive topical antifungal (econazole or terbinafine cream daily for 3 weeks) or a short course of systemic antifungals (terbinafine or itraconazole) in dosage and duration appropriate to the lesion. Stress management or elimination may help, and there are isolated reports of cure in some patients.

If avoidance of allergens identified by patch testing does not improve and the condition remains severe, other treatment options for dyshidrotic eczema may include tap water electrophoresis, intradermal botulinum toxin (100-160 IU), weekly low-dose methotrexate, azathioprine (100-150 mg/day to achieve control, then maintenance doses of 50-100 mg/day), and low-dose external beam radiation therapy.