Dyshidrosis, also known as dyshidrotic eczema or pompholyx, is an uncommon skin condition in which very small, fluid-filled blisters appear on the palms of your hands and the sides of your fingers. The soles of your feet also can be affected.
The blisters that occur in dyshidrosis generally last around three weeks and cause intense itching. Once the blisters of dyshidrosis dry, your skin may appear scaly. The blisters typically recur, sometimes before your skin heals completely from the previous blisters.
Treatment for dyshidrosis most often includes creams or ointments that you rub on the affected skin. In severe cases, your doctor may suggest corticosteroid pills, such as prednisone, that you take by mouth.
The blisters associated with dyshidrosis occur most commonly on the sides of the fingers and the palms, although the soles of the feet also can be affected. The blisters are usually small — about the width of a standard pencil lead — and typically appear in clusters, with an appearance similar to tapioca.
In more-severe cases, the small blisters may merge together to form larger blisters. Skin affected by dyshidrosis can be very itchy or even painful. Once the blisters dry and flake off, which occurs in about three weeks, the underlying skin may be red and tender.
Dyshidrosis tends to recur fairly regularly for months or years.
When to see a doctor
Call your doctor if you have a rash on your hands or feet that doesn't go away on its own.
The cause of dyshidrosis is unknown. However, it can be associated with a similar skin disorder called atopic dermatitis, as well as with allergic conditions, such as hay fever. Eruptions may be seasonal in people with nasal allergies.
Risk factors for dyshidrosis include:
- Stress. Dyshidrosis appears to be more common during times of stress.
- Exposure to certain metals. These include chromium, cobalt and nickel — usually in an industrial setting.
- Sensitive skin. People who develop a rash after contact with certain irritants are more likely to experience dyshidrosis.
- Atopic eczema. Some people with atopic eczema may develop dyshidrotic eczema.
For most people, dyshidrosis is just an itchy inconvenience. For some, however, the pain and itching may limit the use of their hands or feet. Intense scratching can increase the risk of a bacterial infection developing in the affected skin.
You're likely to start by seeing your family doctor. He or she may refer you to a doctor who specializes in skin disorders (dermatologist). Here's some information to help you get ready for your appointment and know what to expect from your doctor.
What you can do
Before your appointment, you may want to write a list that answers the following questions:
- Have you experienced this problem in the past?
- Do you have allergies to certain substances such as rubber, glues, fragrances or nickel?
- Have your stress levels worsened recently?
- What medications and supplements do you take regularly?
- Are you exposed to certain metals or chemicals in the work setting or through hobbies?
What to expect from your doctor
Your doctor is likely to ask you a number of questions, such as:
- When did you first begin experiencing symptoms?
- Have your symptoms been continuous or occasional?
- How severe are your symptoms?
- What, if anything, seems to improve your symptoms?
- What, if anything, appears to worsen your symptoms?
- Are you exposed to chemicals or metals in the work setting or through a hobby?
In most cases, your doctor can diagnose dyshidrosis based on a physical exam. No lab test can specifically confirm a diagnosis of dyshidrosis, but your doctor may suggest tests to rule out other skin problems that have similar symptoms.
For example, a scraping of your skin can be tested for the type of fungus that causes problems such as athlete's foot. Skin allergies and sensitivities can be revealed by exposing patches of your skin to various substances.
Depending on the severity of your signs and symptoms, treatment options may include:
- Corticosteroids. High-potency corticosteroid creams and ointments can help speed the disappearance of the blisters. Wrapping the treated area in plastic wrap can improve absorption. Moist compresses also may be applied after the application of a corticosteroid to enhance the absorption of the medication. In severe cases, your doctor may prescribe corticosteroid pills, such as prednisone. Long-term use of steroids can cause serious side effects.
- Phototherapy. If other treatments aren't effective, your doctor may recommend a special kind of light therapy that combines exposure to ultraviolet light with drugs that help make your skin more receptive to the effects of this type of light.
- Immune-suppressing ointments. Medications such as tacrolimus (Protopic) and pimecrolimus (Elidel) may be helpful for people who want to limit their exposure to steroids. However, these drugs can increase the risk of skin infections.
- Botulinum toxin injections. Some doctors may consider recommending botulinum toxin injections to treat severe cases of dyshidrosis. However, this is a relatively new treatment option that has not yet gained general acceptance.
Home treatment might include:
- Compresses. Wet, cool compresses may help reduce itching.
- Antihistamines. Over-the-counter antihistamine medications such as diphenhydramine (Benadryl) or loratadine (Claritin, Alavert, others) can help relieve itching.
- Witch hazel. Soaking the affected areas in witch hazel may speed healing.
Because the cause of dyshidrosis is generally unknown, there's no proven way to prevent this condition. However, managing stress and avoiding exposure to metal salts, such as chromium and nickel, may help prevent dyshidrosis.