Hard lumps appear on the fingers as soon as they are scratched.

Hard bumps appearing on the fingers upon scratching may be caused by conditions such as urticaria, insect bite dermatitis, or eczema, and treatment should be tailored according to the specific cause. Detailed analysis is as follows:

1. Urticaria

If the hands come into contact with allergens such as animal dander, pollen, or dust, this condition can be triggered, leading to increased local vascular permeability. This results in itching—scratching intensifies the itch—and the formation of hard bumps. Under medical guidance, topical treatments such as calamine lotion or desonide cream may be used for symptom relief.

2. Insect Bite Dermatitis

This is an allergic reaction caused by insect bites, resulting in localized itching. Repeated scratching can enlarge skin damage, manifesting as described above. As directed by a physician, topical medications such as hydrocortisone butyrate cream or compound acetic acid dexamethasone cream can help alleviate symptoms.

3. Eczema

Eczema is a type of allergic skin inflammation that may present as persistent papules and vesicles in affected areas, accompanied by severe itching. Symptoms worsen with scratching. Under medical advice, topical treatments such as tacrolimus ointment or pimecrolimus cream may be used for relief.

In addition to the common causes listed above, other possible causes include allergic dermatitis, tinea manuum (hand fungus), and contact dermatitis. If discomfort occurs, prompt medical evaluation and treatment are recommended to avoid disease progression.