Tretinoin and Azelaic Acid are commonly used in dermatology. Whether they can be used together is related to the efficacy and safety, and doctors and patients are quite concerned.

Retinoin is a tretinoin drug, which can regulate the proliferation and differentiation of epidermal cells, and has significant effect on skin diseases such as acne vulgaris and psoriasis. It can improve the keratinization of hair follicle sebaceous gland ducts, dissolve microacne and acne, anti-inflammatory, and can also promote dermal collagen synthesis and improve photoaging skin.

Azelaic acid, a natural dicarboxylic acid, has antibacterial activity against Propionibacterium acne, can reduce the number of lipid free fatty acids and bacteria on the skin surface, inhibit tyrosinase activity, and reduce pigmentation. It is commonly used in the treatment of acne vulgaris and melasma.

From the pharmacological mechanism, the two roles are complementary. Retinoic acid focuses on improving hair follicle keratinization, anti-inflammatory and anti-proliferation; azelaic acid has both antibacterial, anti-inflammatory and whitening effects. Combined use may enhance the therapeutic effect on acne, and can also improve post-acne pigmentation and skin aging.

However, the combination of the two may increase adverse reactions. Retinoic acid is highly irritating and can cause erythema, desquamation, and burning sensation in the skin. Although azelaic acid is relatively mild, some people may also have slight irritation. Combined use may exacerbate the symptoms of skin irritation, such as redness, itching, and tingling, especially for those with sensitive skin.

In clinical application, in order to reduce adverse reactions, you can start with a low concentration and a small area. Apply one first, and then add another after the skin adapts, and try to use it at intervals. For example, use retinoic acid at night and azelaic acid in the morning. At the same time, do a good job of skin moisturizing and sun protection to reduce discomfort. In short, the combination of retinoic acid and azelaic acid may be a good treatment for skin diseases, but patients must use it under the guidance of a doctor and pay close attention to skin reactions in order to adjust the treatment plan in time.