For inflammatory acne with moderate severity, which treatment should be added to topical retinoids?

In the treatment of moderate inflammatory acne, the addition of topical erythromycin to topical retinoids is grounded in their complementary mechanisms of action. Topical retinoids work by promoting cell turnover and preventing the occlusion of hair follicles, which can lead to acne formation. They also reduce the formation of comedones, the initial lesions in acne.

Topical erythromycin, an antibiotic, acts to reduce the bacterial load of Cutibacterium acnes on the skin. This bacteria is implicated in the inflammatory response associated with acne. By combining a topical retinoid with topical erythromycin, you effectively target both the obstruction of follicles and the inflammation caused by bacteria, leading to a more comprehensive approach to treatment for moderate inflammatory acne.

Using a topical antibiotic like erythromycin helps to mitigate potential resistance issues that can arise with systemic antibiotics while providing localized intervention for the inflammatory lesions. This synergy makes the combination of a topical retinoid with topical erythromycin a first-line recommendation in the management of moderate inflammatory acne.

Other treatments such as benzoyl peroxide, while also effective due to its antibacterial properties, usually complement the regimen differently and were not indicated as the addition to topical retinoids in this scenario. Oral antibiotics and isotretinoin are