Consider insect bite dermatitis caused by flea bites. Insect bite dermatitis is a skin allergy and inflammatory reaction caused by mites, mosquitoes, bedbugs, fleas, bees and other insects that pierce the skin with their mouthparts to suck blood, or inject venom into the human body. Sometimes it is difficult to find the bug itself, so it is classified as insect bite dermatitis. The main similarity is that there are needle-sized bite marks at the bite site, the skin lesions are the same as the bite site, and the itching is unbearable. The severity is related to the insect type and quantity and the patient's sensitivity. Mite dermatitis is characterized by edematous wheal-like papules, papuloherpes, or ecchymoses. Mosquitoes are mainly petechiae, wheals, papules or ecchymoses. Bed bug bites may cause wheal-like papules or itching, with petechiae and blisters in the center, and erythema and purpura. Flea bites mainly form blisters, erythema multiforme or purpura, which are found on the waist and legs. Bee stings are mainly painful, quickly red and swollen, and may cause blisters or even bullae. Those with mild symptoms can use topical glucocorticoid creams such as hydrocortisone butyrate cream and internal antihistamines such as loratadine tablets. Those with extensive skin lesions can take oral anti-inflammatory drugs if the reaction is severe.