What is the cause and treatment for a 2-year history of tiny, pink bumps or spots on the palms of an adult's hands, which are sometimes itchy and have a stinging feeling, but not painful, with no significant past medical history?

Dyshidrotic Eczema (Pompholyx)

The most likely diagnosis is dyshidrotic eczema (pompholyx), a chronic vesicular eruption of the palms characterized by pruritic, small tense vesicles that can cause itching and stinging sensations, and first-line treatment is high-potency topical corticosteroids applied 2-4 times daily. 1, 2, 3

Diagnostic Features

The clinical presentation of tiny pink bumps on the palms with intermittent itching and stinging over 2 years strongly suggests dyshidrotic eczema, which characteristically presents as:

• Pruritic, small tense vesicles on the palms and lateral/ventral surfaces of fingers that can appear like "tapioca pudding" on examination 2, 3
• Recurrent vesicular eruptions that appear suddenly and are very pruriginous 3, 4
• Chronic, relapsing course over months to years, consistent with your 2-year history 2, 5
• The stinging sensation you describe is consistent with the vesicular nature of this condition 3

Critical Differential Diagnoses to Exclude First

Before initiating treatment, you must rule out:

• Palmoplantar psoriasis: Look for well-demarcated erythematous plaques with thick silvery scale and hyperkeratosis, rather than vesicles 6, 7
• Palmoplantar pustulosis: Presents with sterile pustules rather than clear vesicles, often associated with smoking 8
• Contact dermatitis: Obtain history of new exposures, soaps, or occupational irritants 7
• Metal allergy: Consider patch testing if recalcitrant, as metal allergy is an important etiologic factor in dyshidrotic eczema 2

Treatment Algorithm

First-Line Topical Therapy

Initiate hydrocortisone 1% cream or higher potency topical corticosteroid (such as clobetasol propionate 0.05%) applied to affected areas 3-4 times daily 1, 7

• Topical corticosteroids are the cornerstone of therapy for dyshidrotic eczema 4
• For enhanced penetration, use the "soak and smear" technique: soak hands in plain water for 20 minutes, then apply medication to damp skin 7
• Continue treatment until vesicles resolve, typically requiring several weeks 4

Second-Line Options if No Response After 4 Weeks

Refer for topical PUVA (psoralen plus UVA) phototherapy 2-3 sessions weekly, which achieves clearance in 58-81% of dyshidrotic eczema cases 7, 4

• Topical photochemotherapy with methoxsalen is as effective as systemic photochemotherapy 4
• Alternative: Calcineurin inhibitors (tacrolimus, pimecrolimus) also appear effective 4

Third-Line for Severe or Refractory Cases

Systemic therapy with oral corticosteroids or immunosuppressants for bullous or recalcitrant pompholyx 4

• Alitretinoin has demonstrated efficacy in chronic hand dermatitis including pompholyx 4
• Intradermal botulinum toxin injection is an evolving treatment option 4
• Combination therapy yields best results in practice 4

Critical Pitfalls to Avoid

• Do not overdebride lesions: Physical debridement may be used for mild hyperkeratosis, but excessive removal makes underlying skin susceptible to increased blistering and tenderness 7
• Do not dismiss as simple irritant dermatitis: The chronic 2-year course and vesicular nature require specific treatment beyond simple moisturizers 5
• Address quality of life impact: Dyshidrotic eczema causes significant physical discomfort, psychological distress, and occupational impairment despite affecting small body surface area 5, 7
• Consider metal allergy testing: If symptoms persist despite treatment, patch testing for metal allergy (particularly nickel) may identify a treatable trigger 2

Expected Outcomes

Dyshidrotic eczema is challenging to manage and often requires combination treatments for optimal control 4, 5. The condition is recurrent and chronic, so maintenance therapy may be necessary to prevent flares 2, 4. Most patients benefit from starting with high-potency topical corticosteroids and escalating to phototherapy or systemic agents if topical therapy fails after 4 weeks 7, 4.