A red patch appeared when scraping the shoulder.

Redness appearing on the shoulder after scraping may be caused by normal physiological response, allergic reaction, infection, urticaria, or allergic dermatitis. Appropriate management should be based on the specific cause. The details are as follows:

1. Normal phenomenon

Scraping the shoulder often causes minor local skin damage, leading to redness. This is a normal phenomenon and usually resolves on its own without concern.

2. Allergic reaction

If the skin comes into contact with an allergen during scraping, it may trigger a localized allergic reaction, manifesting as red patches. Possible allergens include the scraping tools or skincare products used. Under medical guidance, medications such as cetirizine hydrochloride tablets or loratadine tablets can be used for treatment.

3. Infection

When the shoulder skin is scraped or abraded, bacteria or other pathogens may enter the wound, causing local skin infection. Symptoms of infection include redness, swelling, warmth, and pain. Antibiotics such as levofloxacin tablets or amoxicillin granules may be used under medical supervision to relieve symptoms.

4. Urticaria

Urticaria is an allergic skin reaction that causes raised red welts accompanied by intense itching. It may be triggered by allergic reactions, infections, or other factors. Patients should use topical medications such as compound acetic acid dexamethasone cream or erfukang liniment under medical guidance to alleviate symptoms.

5. Allergic dermatitis

Essential oils may be used during shoulder scraping. If a patient has sensitive skin, using essential oils may provoke an allergic reaction, resulting in red patches or rashes along with itching, swelling, and warmth. In such cases, patients can apply calamine lotion or hydrocortisone butyrate cream locally under medical supervision.

If any of these conditions persist, it is generally recommended to promptly consult a doctor and receive timely treatment to avoid delaying recovery.