Treatment of Infected Genital Skin Tag
For an infected genital skin tag, cephalexin is the appropriate antibiotic choice, as it provides targeted coverage against the most likely pathogens (Staphylococcus aureus and Streptococcus pyogenes) causing skin and soft tissue infections in the genital area. Doxycycline is not indicated for this condition unless there is a concurrent sexually transmitted infection.
Rationale for Antibiotic Selection
Why Cephalexin is Preferred
Cephalexin is FDA-approved specifically for skin and skin structure infections caused by Staphylococcus aureus and Streptococcus pyogenes, which are the primary bacterial pathogens in infected skin tags 1
First-generation cephalosporins like cephalexin provide appropriate Gram-positive coverage needed for mild skin and soft tissue infections, as recommended by the Infectious Diseases Society of America guidelines 2
The typical dosing is cephalexin 500 mg orally four times daily for 7-10 days, depending on severity 1
Why Doxycycline is NOT Appropriate
Doxycycline is indicated for sexually transmitted infections (chlamydia, syphilis, lymphogranuloma venereum) and not for routine skin and soft tissue infections 2
The evidence supporting doxycycline use is exclusively for STI prevention and treatment, including its role in treating chlamydial infections, early syphilis, and as postexposure prophylaxis for bacterial STIs in high-risk populations 2, 3
Doxycycline lacks the targeted Gram-positive coverage necessary for typical skin infections caused by staphylococci and streptococci 2
Clinical Algorithm for Treatment Decision
Step 1: Assess the Infection Type
If the skin tag shows signs of localized bacterial infection (erythema, warmth, purulent drainage, tenderness) without urethral/vaginal discharge or genital ulcers: Use cephalexin 1
If there are concurrent STI symptoms (urethral discharge, dysuria, genital ulcers, inguinal lymphadenopathy): Consider doxycycline 100 mg orally twice daily for 7-21 days depending on the specific STI, but ADD appropriate coverage for the skin infection 2
Step 2: Prescribe Appropriate Therapy
For isolated infected skin tag: Cephalexin 500 mg orally four times daily for 7-10 days 1
For skin tag infection with suspected concurrent chlamydia: Doxycycline 100 mg orally twice daily for 7 days PLUS consider adding cephalexin for the skin component 2, 3
For skin tag infection with suspected concurrent gonorrhea: Ceftriaxone 500 mg IM once PLUS doxycycline 100 mg orally twice daily for 7 days, with cephalexin added if significant skin infection persists 3
Important Clinical Caveats
Common Pitfalls to Avoid
Do not use doxycycline monotherapy for a simple infected skin tag, as it provides inadequate coverage for the typical skin flora causing these infections 2, 1
Do not assume genital location automatically means STI—most infected skin tags are caused by common skin bacteria, not sexually transmitted pathogens 1, 4
Obtain appropriate cultures before initiating therapy when possible, especially if the infection is severe or not responding to initial treatment 1
When to Consider Doxycycline
Only add doxycycline if there is clinical suspicion for concurrent STI based on sexual history, presence of urethral/vaginal discharge, genital ulcers, or known STI exposure 2, 3
For lymphogranuloma venereum affecting perianal/perirectal tissues (which can mimic infected skin tags), doxycycline 100 mg orally twice daily for 21 days is the treatment of choice 2, 4
Monitoring and Follow-up
Reassess within 48-72 hours to ensure clinical improvement with cephalexin therapy 2
If no improvement occurs, consider incision and drainage if abscess is present, obtain cultures, and reassess antibiotic coverage 2
Screen for STIs if risk factors are present (multiple partners, new partner, known STI exposure), as this would change the treatment approach to include doxycycline 3