The effect of long-term use of azelaic acid and those suffering from
azelaic acid, an external agent, is often applied to the treatment of skin diseases. When first used, there may be itching, redness, and desquamation of the skin. This is a sign of skin adaptation, and it can often slow down.

However, if it is used for a long time, its effect may be effective, but there may be hidden concerns. For the skin barrier, long-term application may cause damage. If the barrier is weak, the skin's ability to resist external evil will decrease, and it will be easily invaded by wind evil and heat poison, causing frequent skin sensitivity and itching and pain.

And under long-term use, the function of melanocytes may be disturbed. The metabolism of melanin is abnormal, and in light cases, the skin tone is uneven, and the scars gradually appear; in severe cases, the pigmentation is lost, and diseases such as white purpura may occur. And its regulation in the sebaceous gland, if it is too much, the oil secretion will decrease sharply, the skin will lose moisture, and the pain of dryness and cracking will follow.

Furthermore, if it is applied with azelaic acid for a long time, the body may tolerate it. The efficacy of the drug gradually decreases, and the symptoms of the past recur, and the choice of treatment methods is also limited.

Therefore, doctors use this medicine, often instructing patients to evaluate the situation, observe changes in the skin, and make timely changes, in order to heal the disease without hurting.