How can I effectively treat acne on my back, given that tretinoin (a topical retinoid) keeps my face clear?

From the Guidelines

Tretinoin can effectively treat back acne, and I recommend applying a pea-sized amount of tretinoin (0.025% or 0.05% strength) to affected areas of your back once daily, preferably at night, as it has been shown to be effective in treating acne vulgaris 1. To effectively treat acne on your back, given that tretinoin keeps your face clear, consider the following steps:

• Apply a pea-sized amount of tretinoin (0.025% or 0.05% strength) to affected areas of your back once daily, preferably at night, as it has been shown to be effective in treating acne vulgaris 1.
• Since the back's skin is thicker than facial skin, you might need a slightly higher concentration than what you use on your face.
• Complement this with a benzoyl peroxide wash (4-10%) in the shower, leaving it on for 2-3 minutes before rinsing, as benzoyl peroxide has been shown to be effective in reducing inflammatory lesions 1.
• For hard-to-reach areas, use a long-handled applicator or spray.
• Wear loose cotton clothing after application and sleep in an old t-shirt as tretinoin can bleach fabrics.
• Start with application every other night for two weeks before moving to nightly use to minimize irritation. Tretinoin works by increasing cell turnover and preventing clogged pores, while benzoyl peroxide kills acne-causing bacteria, such as P acnes 1. If this regimen doesn't show improvement after 8-12 weeks, consider seeing a dermatologist for prescription antibiotics or stronger treatments like isotretinoin for severe cases. It's also worth noting that combination agents, such as erythromycin 3%/BP 5% or clindamycin 1%/BP 5%, may be effective in treating acne, but may have rare side effects, such as diarrhea or Clostridium difficile-related colitis with clindamycin topically 1.

From the Research

Treatment Options for Acne on the Back

To effectively treat acne on the back, consider the following options:

• Topical therapies such as retinoids (e.g., tretinoin), benzoyl peroxide, azelaic acid, and/or combinations of topical agents are first-line treatments 2
• Combinations of topical agents with systemic agents (oral antibiotics such as doxycycline and minocycline, hormonal therapies such as combination oral contraception or spironolactone, or isotretinoin) are recommended for more severe disease 2
• Blue-light therapy has been shown to be effective in improving lesions and shortening their time to clearance, with significant differences in reduction in lesion size and erythema compared to placebo 3, 4, 5, 6

Considerations for Treatment

When considering treatment options, keep in mind:

• The severity of the acne, as more severe cases may require combination therapy or systemic agents 2
• The potential for antibiotic resistance, which may make alternative treatments such as blue-light therapy more appealing 4
• The convenience and practicality of treatment regimens, as once-weekly or alternating twice-weekly regimens may be more suitable for some patients 5

Additional Therapies

Additional therapies that may be considered include:

• Photodynamic therapy, which uses blue light to target specific skin conditions 6
• Combination LED phototherapy using blue and red light, which has been shown to be effective in treating inflammatory acne 5