Itchy Palms and Soles Without Rash in a 6-Year-Old
The most likely diagnosis is scabies, and you should treat empirically with permethrin 5% cream applied from head to toe (including scalp, palms, and soles) for 8-14 hours, treating all household contacts simultaneously. 1, 2, 3
Why Scabies is the Primary Diagnosis
In children aged 6 years with isolated pruritus of palms and soles without visible rash, scabies remains the leading diagnosis because:
- Palmar and plantar involvement is characteristic of scabies in infants and young children, unlike adults where these areas are typically spared 3, 4
- Burrows are frequently difficult to find in children, and secondary changes may obscure the classic presentation 3, 4
- The absence of visible rash does not exclude scabies—pruritus often precedes or occurs without obvious skin changes 5, 3
- Recent evidence shows that even older children can present with palmar involvement when infestations are severe or prolonged 6
Critical Differential Diagnoses to Exclude First
Before treating for scabies, rapidly assess for these conditions:
Life-threatening conditions requiring immediate action:
- Check for fever, headache, or tick exposure in the past 2 weeks to exclude Rocky Mountain spotted fever, which requires immediate doxycycline even before diagnostic confirmation 7
- If pregnant (not applicable here but important to note), measure serum bile acids immediately to exclude intrahepatic cholestasis of pregnancy 7
Other important considerations in a 6-year-old:
- Kawasaki disease: Look for 5+ days of high fever (≥39°C), conjunctival injection, oral changes, or lymphadenopathy—requires immediate echocardiography and IVIG 1
- Atopic dermatitis: This characteristically spares palms and soles, making it unlikely with isolated palmar/plantar symptoms 1
- Hand, foot, and mouth disease: Would present with vesicular lesions and typically includes oral involvement, not isolated pruritus 8
Diagnostic Confirmation
Perform a mineral oil scraping to confirm scabies before treatment if possible, but do not delay treatment if clinical suspicion is high 3:
- Scrape suspected areas (interdigital web spaces, wrists, elbows, axillae in addition to palms/soles) 3
- Look for mites, eggs, or fecal pellets under microscopy 3
- Remember that negative scrapings do not exclude scabies in children where burrows are difficult to identify 3, 4
Treatment Protocol
Permethrin 5% cream is the treatment of choice for children with scabies due to high efficacy and low risk of side effects 2, 3:
- Apply thoroughly from head to toe, including scalp, temple, forehead, palms, and soles (infants and children require scalp treatment unlike adults) 2, 3
- Leave on for 8-14 hours, then wash off 2
- Use approximately 30 grams for coverage 2
- One application is generally curative 2
Treat all household members and close contacts simultaneously, even if asymptomatic 3:
- This is imperative to prevent reinfection 3
- Wash all clothing, bedding, and articles of contact in hot water 3
Post-Treatment Expectations and Pitfalls
Persistent pruritus after treatment is common and rarely indicates treatment failure 2:
- Itching may continue for days to weeks after successful mite eradication 2
- This is not an indication for retreatment 2
- Only retreat if demonstrable living mites are found after 14 days 2
Postscabietic nodules may persist for months after clearance 3:
- These are a hypersensitivity reaction and do not require additional scabicide treatment 3
- Some hypothesize infantile acropustulosis may represent a post-scabies hypersensitivity phenomenon 9
When to Reconsider the Diagnosis
If symptoms persist beyond 14 days with no improvement:
- Re-examine for living mites before retreating 2
- Consider alternative diagnoses including atopic dermatitis (though palmar/plantar sparing makes this less likely) 1
- Evaluate for contact dermatitis or other causes of generalized pruritus 5
- Ensure compliance with treatment and simultaneous household treatment 3