What causes the sensation of being bitten by insects when no bugs are visible but welts appear, and what should be done about it?

Generally, the sensation of being bitten by an insect without actually seeing one, but with visible bumps, may be caused by bites from tiny insects, skin friction irritation, urticaria (hives), insect bite dermatitis, or folliculitis. Depending on the specific situation, general care or medical treatments such as medications can be used to improve symptoms. Detailed analysis is as follows:

1. Bites from tiny insects

Bites from tiny insects such as fleas or mites may cause immediate reactions before the insect quickly moves away. Their saliva triggers a localized allergic reaction, resulting in raised bumps. Wash the affected area with clean water, change and boil clothes for disinfection, and maintain a well-ventilated, dry environment.

2. Skin friction irritation

Rough clothing materials or repeated friction can lead to skin tissue congestion and swelling, forming bumps resembling insect bites. Switch to soft cotton clothing, avoid further friction on the affected area, and apply a gentle moisturizer locally.

3. Urticaria (hives)

Exposure to allergens such as pollen or certain foods causes small blood vessels in the skin and mucous membranes to dilate and become congested, leading to wheals accompanied by itching. Avoid known allergens and take antihistamines such as cetirizine hydrochloride tablets, loratadine capsules, or ebastine tablets as directed by a physician.

4. Insect bite dermatitis

Inflammatory reactions occur due to residual insect saliva after a bite, causing swollen, itchy bumps even though the insect is no longer present. Avoid scratching to prevent infection. Follow medical advice to use topical calamine lotion or desonide cream, and take oral fexofenadine hydrochloride tablets if prescribed.

5. Folliculitis

Bacterial infection of hair follicles leads to inflammation, causing red, raised bumps that are often mistaken for insect bites. Maintain good skin hygiene. As directed by a healthcare provider, apply topical mupirocin ointment or fusidic acid cream, and take oral cefradine capsules if necessary.

In daily life, maintain environmental cleanliness and regularly sun-dry clothes and bedding. Take protective measures when going outdoors and avoid areas with dense vegetation or high insect populations. Eat a light diet and reduce intake of spicy or irritating foods. Seek medical attention promptly if the bumps continue to enlarge, develop pus, or are accompanied by fever.