What is the best course of treatment for a female patient who developed a maculopapular rash after completing a course of clindamycin (antibiotic) for a skin cut?

Management of Clindamycin-Induced Maculopapular Rash

Discontinue clindamycin immediately and initiate symptomatic treatment with topical corticosteroids and oral antihistamines, as this represents a non-severe delayed-type hypersensitivity reaction that typically resolves within 1-2 weeks without requiring systemic corticosteroids. 1

Immediate Assessment

Classify the reaction severity using the Dutch Working Party criteria to determine if this is a non-severe versus severe cutaneous adverse reaction 2:

• This patient has a non-severe reaction because the maculopapular exanthema lacks organ involvement, fever >38.5°C, mucosal involvement, skin detachment, or pustules 2
• The timing (2 days post-completion) is consistent with delayed-type hypersensitivity, which typically manifests 1-14 days after drug exposure 3, 4
• Confirm absence of danger signs: no facial edema, no pustules, no purpura, no mucosal erosions, and body surface area involvement <50% 2

Treatment Algorithm

For this non-severe maculopapular rash 2, 1:

1. Stop clindamycin permanently - the patient should avoid all clindamycin and lincomycin-containing products in the future 2, 5

2. Initiate topical therapy:

   • Medium-to-high potency topical corticosteroids (e.g., clobetasol propionate 0.05%) applied twice daily to affected areas 2, 1
   • Emollients and moisturizers to maintain skin barrier 1

3. Add oral antihistamines for pruritus control (e.g., cetirizine 10 mg daily or diphenhydramine 25-50 mg every 6 hours) 1

4. Avoid systemic corticosteroids - they are not indicated for non-severe maculopapular rash without organ involvement 2, 1

Expected Course and Monitoring

• The rash should resolve within 1-2 weeks with appropriate topical treatment 1
• Monitor for progression to severe cutaneous adverse reactions, though this is unlikely given the current presentation 2
• No laboratory testing is required unless systemic symptoms develop (fever, lymphadenopathy, hepatosplenomegaly) 1

Critical Pitfalls to Avoid

Do not continue or rechallenge with clindamycin - this represents confirmed drug hypersensitivity, and re-exposure can lead to more severe reactions including DRESS syndrome (Drug Reaction with Eosinophilia and Systemic Symptoms) 5, 6

Do not label this as "penicillin allergy" - clindamycin is a lincosamide antibiotic structurally unrelated to beta-lactams, and this reaction does not predict penicillin hypersensitivity 2, 7

Watch for delayed severe reactions - while rare, clindamycin can cause severe hypersensitivity reactions including Stevens-Johnson syndrome, toxic epidermal necrolysis, and DRESS syndrome, which may develop up to 2 months after drug exposure 5, 6

Mechanism and Future Considerations

This represents a delayed-type (Type IV) hypersensitivity reaction mediated by T-cells rather than IgE 3, 4:

• Patch testing with clindamycin 10% in petrolatum has 30% sensitivity for confirming the diagnosis if needed for medicolegal purposes, though it is not required for clinical management 4
• Intradermal testing carries risk of generalized reactions and should only be performed in specialized centers if absolutely necessary 8
• The patient can safely receive other antibiotic classes (beta-lactams, fluoroquinolones, macrolides) as there is no cross-reactivity 2, 7

Alternative Antibiotics for Future Use

For future skin and soft tissue infections, the patient can safely receive 7:

• Beta-lactams (amoxicillin, cephalexin) - no cross-reactivity with clindamycin
• Trimethoprim-sulfamethoxazole for MRSA coverage
• Doxycycline as an alternative for anaerobic coverage

Document the allergy clearly in the medical record as "clindamycin - maculopapular rash (delayed hypersensitivity)" to prevent future exposure 2, 5