What are the differential diagnoses for red palms and slightly swollen fingers?

Differential Diagnoses for Red Palms and Slightly Swollen Fingers

The most critical first step is to rule out life-threatening causes: if fever and systemic symptoms are present with recent tick exposure, treat empirically for Rocky Mountain spotted fever with doxycycline immediately, as mortality increases from 5% to potentially fatal with delayed treatment. 1

Life-Threatening Conditions (Rule Out First)

• Rocky Mountain spotted fever presents with maculopapular rash spreading to palms and soles 2-4 days after fever onset, with 5-10% mortality if untreated 1
• Ehrlichiosis involves palms/soles in 30% of adults and 60% of children, with 3% case-fatality rate 1
• Meningococcal infection can present with palmar rash and requires urgent recognition 2
• Syphilis (secondary) can manifest with palmar involvement 2

Critical pitfall: Do not wait for the classic triad (fever, rash, tick bite) before treating suspected RMSF—only a minority present with all three initially 1

Drug-Induced Causes

Hand-Foot Syndrome (Palmar-Plantar Erythrodysesthesia)

• Chemotherapy-induced HFS causes redness, marked discomfort, swelling and tingling in palms, occurring in 6-60% of patients on capecitabine, 5-FU (6-34%), doxorubicin (22-29%), or PEGylated liposomal doxorubicin (40-50%) 3
• Symptoms develop within days to weeks after therapy initiation, though may take up to 6 months depending on pharmacokinetics 3
• Hand-foot skin reaction (HFSR) from BRAF inhibitors (vemurafenib, dabrafenib) or multikinase VEGFR inhibitors (sorafenib 10-62%, cabozantinib 40-60%, sunitinib 10-50%, regorafenib 47%) presents with well-defined painful hyperkeratosis rather than the classic HFS pattern 3

Management approach: For Grade 1-2 HFS, continue drug and apply topical low/moderate steroid; for Grade ≥3, interrupt treatment until Grade 0/1, use oral antibiotics (doxycycline 100mg b.i.d. for 6 weeks), topical steroids, and consider systemic corticosteroids 3

• Other drug-induced causes include amiodarone, gemfibrozil, cholestyramine (with hepatic damage), and topiramate or albuterol (with normal liver function) 4

Rheumatologic and Inflammatory Conditions

Psoriatic Arthritis and Spondyloarthritis

• Dactylitis ("sausage digit") presents as diffuse painful swelling of fingers/toes due to flexor tenosynovitis, occurring in psoriatic arthritis 5
• Recent imaging studies confirm that joint capsule enlargement is not required for the sausage-like appearance 5
• Erythrodermic psoriasis can present with superficial exfoliation of palms and pitting edema of extremities 3

Treatment: Topical clobetasol solution, oral acitretin (25mg daily shows substantial improvement within 2 months), soak PUVA, or 308-nm excimer laser for palmoplantar psoriasis 1

Rheumatoid Arthritis

• Palmar erythema occurs in >60% of patients with rheumatoid arthritis and is associated with favorable prognosis 4

Hematologic Disorders

Myeloproliferative Disorders

• Red fingers syndrome manifests as persistent redness on finger pulps, typically secondary to thrombocythemia or polycythemia vera 6
• Can progress to cold blue swollen painful fingers or black toes due to arteriolar thrombotic occlusions 7
• Aspirin is effective treatment for platelet-mediated microvascular symptoms in myeloproliferative disorders 6, 7

Infectious Causes

Viral Infections

• Hand, foot, and mouth disease presents with small pink macules evolving to vesicular lesions with characteristic distribution on palms and soles 2
• Red fingers syndrome can be secondary to HIV, hepatitis C, or chronic hepatitis B 6
• Manifestations spontaneously regress over months or years without trophic alterations 6

Bacterial Infections

• Blistering distal dactylitis is infection of the volar fat pad of distal fingers, mostly caused by group A beta-hemolytic streptococci 5

Systemic and Metabolic Conditions

Hepatic Disease

• Liver cirrhosis causes palmar erythema in 23% of patients due to abnormal serum estradiol levels 4
• Wilson disease and hereditary hemochromatosis may exhibit palmar erythema with other systemic manifestations 4

Endocrine Disorders

• Thyrotoxicosis causes palmar erythema in up to 18% of patients 4
• Diabetes mellitus presents with palmar erythema in 4.1% of patients (more common than necrobiosis lipoidica diabeticorum at 0.6%) 4

Malignancy

• 15% of patients with both metastatic and primary brain neoplasms may have palmar erythema, postulated to be from increased angiogenic factors and estrogens from solid tumors 4

Dermatologic Conditions

Contact Dermatitis

• Irritant contact dermatitis from frequent hand washing (especially during COVID-19 precautions) and water temperature >40°C 1
• Management: Apply moisturizer after every hand wash, use lukewarm water, and apply moderate-to-high potency topical corticosteroids 1

Vesicular Hand Dermatitis

• Acute and recurrent vesicular hand dermatitis (pompholyx, dyshidrotic eczema) presents with symmetric vesicular/bullous eruptions on palms and palmar aspects of fingers 8

Physiologic Causes

Primary Palmar Erythema

• Occurs in at least 30% of pregnant women due to alterations in skin microvasculature function 4
• Can be hereditary, idiopathic, or associated with atopic diathesis 4
• No treatment indicated for primary forms 4

Environmental Causes

• Chronic mercury poisoning and smoking are environmental causes of palmar erythema 4
• Erythema ab igne can mimic palmar erythema 4