What causes intense itching after being bitten by a tiny black insect, and what should I do about it?

Generally, intense itching after being bitten by a small black insect may be caused by allergic reactions, saliva irritation, bacterial infection, parasitic infection, papular urticaria, or other reasons, and targeted treatment is required. It is recommended to seek medical diagnosis and treatment promptly. Specific analysis is as follows:

1. Allergic Reaction

When bitten by a small black insect, substances secreted by the insect's mouthparts or the insect itself may trigger an allergic reaction in the body, causing the immune system to release histamine and other substances that induce local inflammation. The skin may develop redness, swelling, and obvious itching, possibly accompanied by itchy patches or papules, sometimes appearing around the bite area. It is recommended to follow medical advice and take medications such as cetirizine hydrochloride oral solution, loratadine tablets, or ketotifen fumarate capsules to relieve symptoms.

2. Saliva Irritation

During biting, small black insects may release saliva containing chemicals that irritate the skin, leading to itching. Similar to allergic reactions, localized redness, swelling, edema, and intense itching may occur. According to medical advice, topical treatments such as compound dexamethasone cream, vitamin E cream, or acetic acid prednisolone cream can be used for relief.

3. Bacterial Infection

After being bitten, if the skin is broken, bacteria may enter the wound and cause infection, resulting in local inflammation and itching. The affected skin may become red, swollen, and exude fluid, and pus may even form. Under medical guidance, topical antibiotics such as mupirocin ointment, fusidic acid sodium ointment, or compound polymyxin B ointment can be applied for treatment.

4. Parasitic Infection

Some small black insects may serve as hosts for parasites, and their bites could transmit parasites, causing infection and subsequent skin lesions and itching. In addition to localized itching, the bitten skin may develop rashes or ulcers. Treatment may include antiparasitic medications such as albendazole tablets, chloroquine phosphate tablets, or artemether-lumefantrine tablets, based on medical recommendations.

5. Papular Urticaria

After being bitten by a small black insect, patients may develop papular urticaria—an allergic skin condition related to hypersensitivity of the immune system. Skin lesions typically appear as red wheals with relatively flat centers and slightly raised borders, accompanied by severe itching. According to medical advice, medications such as ephedrine-diphenhydramine tablets, compound beclomethasone camphor cream, or erfukang lotion may be used to alleviate symptoms.

Patients should avoid scratching and maintain a light diet to prevent wound infection.