What treatment options are available for itchy pimples on the arms in a patient currently applying Mupirocin (mupirocin)?

Treatment of Itchy Pimples on Arms While Using Mupirocin

If mupirocin alone is not resolving itchy pimples on the arms, add a moderate-to-high potency topical corticosteroid (such as betamethasone valerate 0.1% or mometasone furoate 0.1% ointment) applied to the affected areas for 2-3 weeks, combined with an oral antihistamine for symptomatic relief of pruritus. 1

Initial Assessment and Continued Mupirocin Use

• Continue mupirocin 2% ointment application to the affected areas, as it remains appropriate for treating bacterial skin infections including folliculitis-type lesions ("pimples") 1, 2
• Since the lesions are stable (not increasing), this suggests the infection is controlled but inflammation and pruritus persist 1
• Mupirocin should be applied 2-3 times daily for 5-10 days for optimal efficacy 2, 3

Adding Topical Corticosteroids for Inflammation and Itch

For the body (arms), apply a moderate-to-high potency topical corticosteroid:

• Betamethasone valerate 0.1% ointment OR 1
• Mometasone furoate 0.1% ointment OR 1
• Elocon (mometasone 0.1%) 1

Application strategy:

• Apply topical steroid once or twice daily for 2-3 weeks, then reassess 1
• Use ointment formulation if skin is dry; cream if skin is weeping 1
• Short-term use (2-3 weeks) minimizes risk of steroid-related adverse effects 1

Systemic Treatment for Pruritus

Oral antihistamines for daytime:

• Second-generation non-sedating antihistamines (loratadine 10 mg daily) as first-line choice 1
• These provide symptomatic relief without sedation that could impair daily activities 1

For nighttime pruritus:

• First-generation antihistamines (diphenhydramine 25-50 mg or hydroxyzine 25-50 mg) may be used based on their sedative properties 1
• Warn patients about sedative effects on driving and operating machinery 1

Adjunctive Measures

Emollient therapy:

• Apply emollients regularly (30-60 g per both arms every 2 weeks) to prevent skin dryness which can worsen pruritus 1
• Use aqueous emollients and soap substitutes rather than regular soaps 1

Lotions containing urea or polidocanol may also help soothe pruritus 1

When to Escalate Treatment

If no improvement after 2 weeks of the above regimen:

• Consider GABA agonists (pregabalin 25-150 mg daily or gabapentin 900-3600 mg daily) as second-line treatment for persistent pruritus 1
• Reassess for alternative diagnoses or complications 1

If lesions worsen or spread despite treatment:

• Consider oral antibiotics (doxycycline or cephalexin) if deeper infection or extensive involvement develops 1, 2
• Discontinue mupirocin if signs of sensitivity reaction occur (worsening erythema, severe irritation) 3

Important Cautions

• Avoid prolonged mupirocin use beyond 10 days to prevent resistance development 2, 3
• If no improvement in 3-5 days, contact healthcare provider as per FDA labeling 3
• Monitor for signs of chemical irritation or allergic reaction to mupirocin (increased burning, erythema) 3
• Topical steroids should be used judiciously and for limited duration to minimize adverse effects 1