Reading the 2024 Acne Guidelines: How Treatments Are Graded and Why Antibiotics Are Rationed

When the 2024 American Academy of Dermatology (AAD) acne guidelines rate a treatment, they answer two questions at once and keep the answers apart: how strongly do we recommend this, and how sure are we of the evidence behind it. Published in the Journal of the American Academy of Dermatology by Reynolds and colleagues, the update runs 18 evidence-based recommendations and 5 good practice statements through the GRADE framework. Benzoyl peroxide, topical retinoids, topical antibiotics, oral doxycycline and their fixed-dose combinations all earn strong recommendations at moderate certainty. A topical antibiotic used on its own is the notable exception: it is specifically not recommended, and a thread of antibiotic stewardship runs through the whole document.

Key points#

• GRADE rates two things separately: recommendation strength (should you use it) and certainty of evidence (how solid the data are).
• Strong recommendation does not require top-grade evidence, and top-grade evidence does not force a strong recommendation.
• Benzoyl peroxide and retinoids sit in the strong tier on decades of consistent benefit, even though their certainty is graded moderate.
• Two newer drugs, clascoterone and sarecycline, have high-certainty trials but only conditional recommendations, largely because of cost and access.
• Topical antibiotics are never endorsed alone; every antibiotic recommendation is tied to benzoyl peroxide or a second mechanism.

Two scores that can disagree#

The most common misreading of any guideline is to collapse "strong recommendation" and "high-quality evidence" into a single grade. GRADE splits them on purpose. Recommendation strength weighs the whole picture: benefits against harms, plus patient values, cost and how practical the treatment is to use. Certainty of evidence measures something narrower, namely how much the trial data alone can be trusted. Because the two scores come from different inputs, they can pull in opposite directions.

Acne care shows both directions at once. Benzoyl peroxide and topical retinoids carry strong recommendations while their certainty is rated moderate rather than high. Two newer agents flip that pattern. Clascoterone, a topical androgen-receptor inhibitor, and sarecycline, a narrow-spectrum oral tetracycline, each rest on high-certainty trials yet receive only conditional recommendations. The trials were well designed, so the data are strong, but the guideline points to the drugs' current cost, which may limit fair access, as the reason for the more tentative endorsement. Meanwhile the older topicals stayed in the strong tier on the weight of decades of reliable results. If you read only the headline grade you would draw the wrong conclusion in both cases.

Why benzoyl peroxide anchors the strong tier#

Benzoyl peroxide sits at the heart of the guideline for two reinforcing reasons. It acts on several of the drivers of acne at once, and it clears bacteria without breeding resistant strains, something antibiotics cannot claim. That second property is why the guideline never lets a topical antibiotic stand alone: it pairs the antibiotic recommendation with benzoyl peroxide so that resistant Cutibacterium acnes has less room to emerge.

Think of it as a partner that keeps the antibiotic honest. The antibiotic thins out the bacterial population, and the benzoyl peroxide mops up the survivors that would otherwise carry resistance forward. Used together, they treat the acne and protect the drug class in the same step.

Retinoids and the logic of combining mechanisms#

Topical retinoids reach the strong tier by a different route. They regulate how skin cells mature and shed, which addresses the plugged follicle that forms before a visible pimple, and they calm inflammation on top of that. Because retinoids and benzoyl peroxide work on separate steps of the same process, the guideline treats them as complementary rather than as substitutes for each other.

That same reasoning carries into the fixed-dose combination products. A topical antibiotic plus benzoyl peroxide, a retinoid plus benzoyl peroxide, and a retinoid plus a topical antibiotic each earn strong recommendations. The recurring idea is not one hero ingredient but several mechanisms stacked so they cover the gaps a single agent would leave.

The rule against antibiotic monotherapy#

On one point the guideline is unusually blunt: a topical antibiotic used by itself is not recommended. The reasoning is biological. An antibiotic applied alone subjects skin bacteria to selective pressure with no partner to clear the resistant survivors, which is exactly the setup that breeds resistance. Spread across years of heavy use, that pattern has produced measurable resistance in C. acnes, and it chips away at the usefulness of the entire antibiotic class for a condition that is common and often treated for months at a time.

So the guideline does not retire topical antibiotics. It refuses to let them work solo. Every strong recommendation that includes an antibiotic ties it to benzoyl peroxide or to a second mechanism. Clinical benefit and stewardship line up here: the pairing treats acne better and shields the drug class at the same time. This is where the two-score system earns its keep, because a therapy can be endorsed and fenced in at once, and a single letter grade would hide half of that.

Stewardship built into the design#

Beyond the individual drugs, the guideline hands several of its good practice statements to antibiotic stewardship as a standing principle. It urges clinicians to limit systemic antibiotics where possible, both to slow resistance and to avoid other antibiotic-related complications. When an oral antibiotic is genuinely needed, the guidance favors the shortest effective course, generally no more than three to four months, always paired with benzoyl peroxide and other topical therapy so the systemic drug never carries the case alone. For topical regimens, it recommends combining agents that work by different mechanisms to improve response and lower resistance risk.

Two details are worth noticing. First, these are labeled good practice statements rather than graded recommendations, a GRADE category reserved for guidance so firmly rooted in basic principle and indirect evidence that a formal certainty rating would mislead. Second, they keep oral isotretinoin in reserve for severe, scarring or treatment-resistant disease, or where the psychosocial burden is high, positioning a powerful therapy by need rather than by convenience. Taken together, the recommendations describe care in which mechanism diversity and antibiotic restraint are part of the blueprint, not add-ons.

The useful skill here is less about acne and more about how you read a guideline. A strong recommendation signals confidence that benefits outweigh harms for most people. The certainty grade tells you how firm the evidence is. And a remark such as "not recommended as monotherapy" can matter as much as the headline endorsement it sits beside.