What causes red warm hands?

Causes of Red, Warm Hands

Red, warm hands most commonly result from contact dermatitis (irritant or allergic), erythromelalgia, or heat-related vasodilation, with contact dermatitis being the most frequent culprit in clinical practice.

Primary Differential Diagnoses

Contact Dermatitis (Most Common)

• Irritant contact dermatitis (ICD) accounts for 80% of hand dermatitis cases and presents with erythema, edema, and warmth, particularly after exposure to soaps, detergents, frequent hand washing, or alcohol-based sanitizers 1.
• ICD does not require prior sensitization and can occur on first exposure to irritants such as hot water, harsh soaps, or disinfectants 1.
• Allergic contact dermatitis (ACD) presents similarly with erythema and warmth but requires prior sensitization to specific allergens including preservatives, fragrances, rubber accelerators in gloves, or propylene glycol 1.
• Both ICD and ACD can present acutely with erythema, edema, and vesicle formation, or chronically with lichenification 1.

Erythromelalgia (Consider When Episodic and Painful)

• Erythromelalgia is characterized by episodic burning pain with erythema and warmth of the hands (though feet are more commonly affected), triggered by physical activity, warm temperatures, or exercise 1.
• This rare disorder involves vasodilation of thermoregulatory arteriovenous anastomoses and is relieved characteristically by cooling the affected areas 1.
• Approximately 5% of cases are associated with myeloproliferative diseases (essential thrombocythemia, polycythemia vera), and another 5% have genetic mutations in the SCN9A gene 1.
• Patients with erythromelalgia have significantly lower quality of life, increased morbidity and mortality, and increased suicide risk, making early recognition critical 1.

Heat-Related Vasodilation

• Heat edema presents with warmth and redness of the extremities due to peripheral vasodilation in response to high environmental temperatures 2.
• This is typically benign, self-limited, and resolves with cooling and rest 2.

Critical History Elements to Obtain

For Contact Dermatitis

• Recent changes in hand hygiene practices, including increased washing frequency or new sanitizers 3, 4.
• Occupational exposures (healthcare workers, food service, cleaning, hairdressing) 3, 4.
• Use of gloves (latex, nitrile, vinyl), topical antibiotics (neomycin, bacitracin), or adhesive bandages 1, 4.
• Exposure to known irritants: hot water, dish detergent, bleach, or disinfectant wipes 1.

For Erythromelalgia

• Episodic nature of symptoms with clear triggers (exercise, warm ambient temperature, standing) 1.
• Relief with cooling measures (though extreme cooling with ice water should be avoided) 1.
• Associated burning pain that dominates the clinical picture 1.
• Family history of similar symptoms (suggests inherited form) 1.
• History of myeloproliferative disorders or autoimmune conditions 1.

Immediate Management Approach

For Suspected Contact Dermatitis

• Stop all harsh soaps, detergents, fragrances, and potential irritants immediately 3, 4.
• Use lukewarm or cool water only—avoid hot water 1, 3.
• Pat dry gently without rubbing 1, 3.
• Apply moisturizer immediately after hand washing using two fingertip units for adequate coverage 1, 3.
• Apply medium-potency topical corticosteroid to affected areas for acute flares 3, 4.
• For severe cases, implement "soak and smear" technique: soak hands in plain water for 20 minutes, then immediately apply moisturizer to damp skin nightly for up to 2 weeks 1, 3.

For Suspected Erythromelalgia

• Avoid ice or water immersion, which can lead to tissue damage, ulcerations, and immersion foot 1.
• Use safe cooling measures such as cool (not cold) water, elevation, and fans at a distance 1.
• Counsel patients to continue normal activities and exercise despite symptoms, as avoiding triggers does not improve long-term outcomes 1.
• Consider aspirin trial if myeloproliferative disease is suspected, as this form is more likely to respond 1.

When to Pursue Specific Diagnostic Testing

Patch Testing

• Indicated for suspected ACD when history suggests allergic trigger or when dermatitis persists despite removing obvious irritants 3, 4.
• Essential for recalcitrant cases or change in baseline dermatitis pattern 3, 4.

Workup for Erythromelalgia

• Complete blood count to evaluate for myeloproliferative disorders (essential thrombocythemia, polycythemia vera) 1.
• Consider electromyography and nerve conduction studies, as large fiber neuropathy is present in almost 50% of patients 1.
• Thermoregulatory sweat testing shows marked abnormalities in approximately 90% of patients with erythromelalgia 1.

Escalation Criteria and Referral

Refer to Dermatology When:

• No improvement after 6 weeks of appropriate treatment for contact dermatitis 3, 4.
• Suspected ACD requiring patch testing 3, 4.
• Change in baseline dermatitis pattern 3, 4.
• Recalcitrant hand dermatitis requiring phototherapy or systemic therapy 1, 3.

Refer to Appropriate Specialist for Erythromelalgia:

• Confirmed or suspected erythromelalgia requires multidisciplinary management involving dermatology, vascular medicine, neurology, or pain medicine 1.
• Early treatment is essential to prevent progression to debilitating chronic pain syndrome 1.

Common Pitfalls to Avoid

• Do not use disinfectant wipes for hand cleaning, as harsh disinfectants cause chemical irritation 1.
• Avoid washing hands immediately before or after using alcohol-based sanitizers, which increases dermatitis risk 1, 4.
• Do not apply topical antibiotics (neomycin, bacitracin) to inflamed hands, as these are common allergens 4.
• Avoid superglue (ethyl cyanoacrylate) to close fissures, as it is a known allergen 1, 4.
• For erythromelalgia patients, do not recommend ice water immersion despite patient requests, as this leads to tissue damage 1.