What skin conditions are treated with clarithromycin?

Skin Conditions Treated with Clarithromycin

Clarithromycin is primarily used for bacterial skin and soft tissue infections caused by susceptible organisms, particularly in patients with beta-lactam allergies, and has specialized efficacy against atypical mycobacterial skin infections including Mycobacterium marinum and Mycobacterium chelonae. 1, 2

Primary Indications for Skin Infections

Bacterial Skin and Soft Tissue Infections

• Clarithromycin 250 mg twice daily for 5-14 days is effective for uncomplicated skin and skin structure infections caused by susceptible Gram-positive organisms, demonstrating equivalent efficacy to cefadroxil and erythromycin in multicenter trials 1
• The drug provides an important alternative in beta-lactam allergic patients who cannot tolerate first-line agents like cephalexin or dicloxacillin 1
• Clarithromycin demonstrates activity against Staphylococcus aureus and Streptococcus species, though strains resistant to erythromycin will also be resistant to clarithromycin 2

Impetigo

• Pustular and bullous impetigo respond well to clarithromycin, particularly when caused by Staphylococcus aureus 3
• While considered second-choice therapy compared to topical mupirocin or oral dicloxacillin, clarithromycin has demonstrated high effectiveness in documented cases 3

Specialized Mycobacterial Skin Infections

Mycobacterium marinum Infections (Fish Tank Granuloma)

• Clarithromycin combined with ethambutol represents optimal therapy for M. marinum skin infections, providing the best balance of efficacy and tolerability 4
• Treatment duration should be 3-4 months total, continuing 1-2 months after symptom resolution 4
• The combination of clarithromycin and rifampin achieved 93% cure rates in localized infections and 72% in deep structure involvement in a French study of 63 patients 4
• For osteomyelitis or deep structure infection, add rifampin to the clarithromycin-ethambutol regimen 4

Mycobacterium chelonae Cutaneous Infections

• Clarithromycin 500 mg twice daily for 6 months as monotherapy is highly effective for disseminated cutaneous M. chelonae infections, even in immunosuppressed patients 5
• In a trial of 14 patients (10 with disseminated disease), all had excellent responses with negative cultures after 1 month of therapy 5
• After completing 4.5-9 months of treatment, 9 patients followed for 6-12 months showed no relapse 5
• This may be the drug of choice for cutaneous disseminated M. chelonae disease, particularly valuable since patients were maintained on immunosuppressive therapy (corticosteroids or cyclophosphamide) 5

Mycobacterium mucogenicum Infections

• Clarithromycin is among multiple effective agents for this organism, which causes catheter-related infections and occasionally skin infections 4

Important Clinical Considerations

Antimicrobial Spectrum

• Clarithromycin has greater in vitro activity than erythromycin against Bacteroides melaninogenicus, Chlamydia species, various mycobacteria, and Legionella species 2
• The drug forms a microbiologically active 14-hydroxy metabolite that enhances antimicrobial activity, particularly against Haemophilus influenzae when combined with the parent compound 2

Dosing and Administration

• Standard dosing for skin infections: 250 mg twice daily 1
• For mycobacterial infections: 500 mg twice daily 5
• The twice-daily regimen offers improved compliance compared to erythromycin's four-times-daily dosing 2

Critical Warnings

• Cross-resistance exists with erythromycin - bacterial strains resistant to erythromycin are generally resistant to clarithromycin 2
• Clarithromycin inhibits the CYP3A enzyme system, creating potential for significant drug interactions with medications metabolized by this pathway 4
• Contraindicated in infants under 1 month of age due to unknown association with infantile hypertrophic pyloric stenosis 4
• FDA Pregnancy Category C - animal studies show adverse fetal effects 4
• Dosage adjustment required in renal impairment, though not needed for hepatic impairment alone 4

Common Pitfalls to Avoid

• Do not use clarithromycin as monotherapy for cellulitis without culture confirmation, as Group A Streptococcus coverage may be inadequate in severe infections 6
• Noncompliance with mycobacterial treatment can lead to resistance - one patient who discontinued therapy prematurely after 3.5 months relapsed with a clarithromycin-resistant isolate 5
• Gastrointestinal side effects (epigastric distress, nausea, diarrhea) are common but generally mild 4
• Rare hypersensitivity reactions including fixed drug eruption have been reported 7