Pompholyx, also known as dyshidrotic eczema, is a recurrent non-inflammatory blistering disease that occurs on the palms, soles, and the sides or between the fingers and toes. It is often accompanied by profuse sweating of the hands and feet, tends to occur in spring and summer, and may persist for several months with a tendency to recur the following year.

bubble_chart Etiology

Dyshidrotic eczema is a type of eczema. In the past, it was mistakenly believed to be caused by profuse sweating or poor perspiration, leading to clusters of small blisters on the palms and soles, hence the name "dyshidrotic eczema." However, this condition also occurs in individuals with reduced sweating, and histological examinations in most cases fail to establish a connection between the blisters and sweat ducts. Therefore, the condition is not directly related to profuse sweating. Psychological factors are significant triggers for this disease. Recently, it has been discovered that nickel allergies can also cause it.

bubble_chart Clinical Manifestations

The typical lesion is a round blister, ranging from the size of a rapeseed to a soybean, located deep in the epidermis. It appears hemispherical and slightly raised above the skin surface, without inflammatory reaction. These blisters may occur sporadically or in clusters, rarely on the back of the hands or soles of the feet, and are often symmetrically distributed. There is no surrounding erythema, and the blister fluid is initially clear but later becomes turbid. The blisters may merge to form larger bullae. They usually do not rupture spontaneously and often resolve on their own within 2–3 weeks, forming collar-like desquamation and revealing red new epithelium. In severe cases, the entire palm may exhibit diffuse desquamation. Symptoms include cutaneous pruritus or a burning sensation.

1. It commonly occurs on the palms and the sides of the fingers;
2. The lesions are multiple rice-grain-sized deep-seated vesicles, hemispherical in shape, slightly raised above the skin surface, occurring in clusters with symmetrical distribution;
3. There is a sensation of burning and cutaneous pruritus;
4. It is more common in summer and often recurs seasonally;
5. Patients often have profuse sweating of the hands and feet.

bubble_chart Treatment Measures

Treatment Principles

1. Systemic therapy;
2. Local treatment: mainly focusing on astringency and antipruritic effects;
3. Superficial X-ray radiation therapy may be used as appropriate.

1. Short-term oral prednisone can yield rapid results. Sedatives or antihistamines may be appropriately administered for emotionally tense patients. Anticholinergic drugs such as atropine may be used when necessary.
2. Topical corticosteroid creams or ointments can be applied. For cases with repeated local desquamation, dryness, and pain, 2–5% salicylic acid ointment or 10% urea cream may be used externally.

bubble_chart Cure Criteria

1. Cure: Subjective symptoms disappear and skin rash subsides;
2. Improvement: Subjective symptoms alleviate, most of the skin rash subsides with occasional recurrence;
3. No cure: Both subjective symptoms and skin rash show no improvement.

bubble_chart Differentiation

Differentiation from tinea pedis: Dyshidrotic eczema commonly occurs on the hands and feet. When it appears on the soles of the feet, the blisters rupture and dry out, leading to peeling, which can be easily confused with the blisters and peeling caused by tinea pedis. However, dyshidrotic eczema presents with numerous small blisters on the soles and sides of both feet, while the toe webs remain unaffected, and microscopic examination shows no fungal infection.