White, particularly hard small spots on the thumb

White, hard small spots on the thumb are usually caused by conditions such as eczema, dyshidrotic eczema (pompholyx), or tinea manuum (fungal infection of the hand). Patients are generally advised to use medications under the guidance of a doctor. Specific analysis is as follows:

1. Eczema

Eczema on the thumb is often associated with environmental irritants, allergies, and other factors. It can lead to localized white papules or papulovesicles that feel firm, accompanied by itching, stinging, or discomfort. It is usually recommended to apply topical medications such as desonide cream or tacrolimus ointment under medical supervision.

2. Dyshidrotic eczema (Pompholyx)

This condition commonly occurs during spring and summer, manifesting as firm blisters or white spots on the hands. Often there are no obvious symptoms, although some patients may experience local pain or itching. Treatment options under a doctor's guidance may include triamcinolone acetonide acetate cream or pimecrolimus cream.

3. Tinea manuum (Hand fungus)

This is usually caused by a fungal infection and is somewhat contagious. White spots or blisters appear on the skin surface, often accompanied by symptoms such as itching, pain, and scaling. It is recommended to use topical antifungal agents such as compound clotrimazole cream or ketoconazole cream under medical supervision to relieve symptoms.

In addition to the common causes mentioned above, other possible factors include neurodermatitis, common warts, or herpes simplex. Patients should avoid scratching the affected area to prevent secondary infection.