What causes small, itchy blisters on the top of the foot?

Generally, small itchy blisters on the top of the foot may be caused by excessive sweating, friction and pressure, eczema, contact dermatitis, hand-foot-and-mouth disease, or other reasons. If discomfort occurs, it is recommended to seek medical attention promptly. Specific analyses are as follows:

1. Excessive Sweating

Excessive sweating of the feet, especially in hot and humid environments, can lead to moist skin on the top of the foot, creating conditions favorable for bacterial or fungal growth, which may result in blisters accompanied by itching. Keep feet dry, change socks frequently, and use moisture-absorbing cotton socks.

2. Friction and Pressure

Friction and pressure can damage the outer layer of the skin, forming fluid-filled cavities between the epidermis and dermis—commonly known as blisters. Blisters caused by this mechanism are often itchy because chemical substances released from injured skin stimulate nerve endings, triggering an itching sensation. Avoid further friction and pressure, wear well-fitting shoes, and use soft pads to protect affected areas.

3. Eczema

Eczema is primarily caused by dampness, poor ventilation, and clogged pores. It compromises the skin barrier on the feet, leading to small blisters and itching on the top of the foot. Symptoms may also include redness, papules, and oozing. Patients may use medications such as desonide cream, fexofenadine hydrochloride tablets, or erythromycin ointment under medical guidance.

4. Contact Dermatitis

Contact dermatitis is an inflammatory reaction triggered by skin exposure to foreign substances. When the skin on the top of the foot comes into contact with irritants or allergens, the immune system responds by releasing chemicals that cause inflammation, potentially resulting in blisters and itching. Symptoms may also include a burning sensation or swelling. Patients may be treated with medications such as loratadine tablets, compound chlorphenamine tablets, or hydrocortisone tablets under a doctor’s supervision.

5. Hand-Foot-and-Mouth Disease

Hand-foot-and-mouth disease is a contagious illness caused by enteroviruses. After invading the body, the virus replicates in the skin and mucous membranes, triggering an inflammatory response that leads to the symptoms described. Additional symptoms may include oral ulcers, fever, and loss of appetite. Treatment should follow medical advice and may include medications such as ibuprofen granules, acetaminophen granules, or ribavirin tablets.

It is recommended to maintain healthy lifestyle habits, balance work and rest, and avoid excessive fatigue to promote overall health.