Dyshidrotic Eczema: Blisters on the Hands, Fingers, and Feet

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Summary of article: TL; DR

• What it is: Dyshidrotic eczema is a skin condition characterized by itchy blisters, located mainly on the hands and feet.
• Duration: the vesicles last for three to four weeks, followed by dryness and peeling of the skin.
• Who usually gets it: it affects more teenagers and adults, rarely children and the elderly.
• Causes: uncertain origin, but associated with factors such as a history of atopic dermatitis, allergies, exposure to metals, irritants, fungi, stress, among others.
• Symptoms: itching, formation of multiple blisters, pain in some cases. The hands are the most affected area.
• Severity: varies from mild to severe, based on the extent and intensity of the symptoms.
• Diagnosis: mainly clinical, additional tests are only necessary in atypical cases.
• Treatment: depends on the severity, ranging from general skin care and topical corticosteroids to systemic treatments and phototherapy.
• Diet: in some cases, reducing foods rich in nickel or cobalt can help.

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What is Dyshidrosis?

Dyshidrosis, also known as dyshidrotic eczema, is a skin condition characterized by a rash in the form of vesicles (small blisters with fluid inside) that are very itchy and usually appear on the hands, especially the palms and the soles of the feet.

These small blisters last about three to four weeks. As they dry out, the skin becomes dry and may flake and crack.

Dyshidrotic eczema affects adolescents and adults, with a peak incidence between the ages of 20 and 40. Infants and older adults are rarely affected.

The disease is more common in hot weather and can be acute, recurrent, or chronic, as shown below.

Causes

The term “dyshidrotic” is derived from the Greek words “dys” which means bad or difficult, and “hidros” which means sweat. The term was coined under the belief that the condition was related to sweat glands, although this has since been disproven.

Today, we no longer believe that the sweat-producing glands have anything to do with the appearance of the blisters, although we still don’t know precisely why dyshidrosis occurs.

Although in most cases no causative or predisposing factor can be established, several risk factors have been identified. The most common are:

• Personal or family history of atopic dermatitis.
• Personal or family history of allergies, such as contact dermatitis, asthma or allergic rhinitis.
• Exposure to metals that commonly cause allergies, such as nickel or cobalt.
• Exposure to irritants.
• Fungal infection of the skin, even if located away from the hands and feet, such as ringworm.
• Use of intravenous immunoglobulin.
• Hyperhidrosis (excessive sweating).
• Smoking.
• Exposure to ultraviolet light.
• Physical or emotional stress.
• Genetic predisposition.
• HIV infection.

Symptoms

Episodes of dyshidrotic eczema usually begin with itchy hands, followed by the sudden appearance of blisters on the palms, fingers, and sides of the hands or soles of the feet, which can be itchy or painful.

In 70 to 80% of patients, only the hands are affected. In milder cases, the vesicles may appear only on the sides of the fingers and occupy a very limited area.

Only 10% of patients with dyshidrosis have lesions exclusively on the feet, sparing the hands.

The blisters are typically small and grouped, often forming a “tapioca” appearance. The small blisters may coalesce to form larger blisters. In some patients, the lesions are so itchy that they interfere with daily activities.

The vesicles usually persist for 3 to 4 weeks, then dehydrate and disappear, causing the skin to peel.

Episodes of dyshidrosis may be recurrent, occurring monthly, or sporadic, occurring no more than once a year.

In some patients, flare-ups may be associated with emotional or physical stress, but most often, they occur in the absence of any identifiable trigger.

When patients have frequent episodes, they can develop chronic dermatitis of the hands or feet, characterized by reddish plaques, thickening of the skin, scaling lesions, and cracks.

The wounds promote bacterial infection of the skin, especially episodes of cellulitis caused by Staphylococcus aureus.

Recurrent episodes can also affect the nails, causing changes in their shape and color.

Severity of symptoms

The severity of dyshidrosis is usually assessed according to the intensity of the blisters and the patient’s symptoms.

We consider dyshidrotic eczema to be mild to moderate if it has the following characteristics:

• It does not involve the entire palmar or plantar surface.
• There are few grouped or scattered blisters.
• There is little redness.
• The patient does not complain of intolerable itching, burning, or pain.

We consider dyshidrotic eczema to be severe when it presents with the following features:

• Involvement of the entire palmar or plantar surface.
• Large vesicles or blisters that are disabling and interfere with the patient’s ability to walk or use their hands for activities.
• Intense pain or itching.

Diagnosis

In most cases, the diagnosis is made through clinical history and physical examination, with no need for additional tests.

It is common for patients to have more than one type of eczema at the same time, such as dyshidrosis and atopic eczema. It is also possible to have a fungal infection associated with dyshidrotic lesions, such as athlete’s foot.

In these cases, the appearance of the lesions may not be very typical and additional tests, such as a skin scraping or biopsy, may help establish the correct diagnosis.

Treatment

Dyshidrotic eczema is a recurrent disease, and patients usually suffer from frequent attacks over many years.

Episodes tend to become less frequent with age, and many patients spontaneously remit at some point in their lives.

Treatment for dyshidrosis is indicated in the most severe cases, with intense symptoms, especially itching or pain, or when the disease occurs very frequently.

General measures

Identifying and avoiding irritants and exacerbating factors is beneficial for most patients with dyshidrotic eczema.

General skin care measures aimed at reducing skin irritation and restoring the skin barrier include

• Wash hands with warm water and soap-free cleansers.
• Thoroughly dry hands after washing.
• Apply moisturizers immediately after drying hands or feet.
• Wear vinyl gloves lined with cotton or other non-latex gloves when performing household tasks involving water.
• Remove rings, watches, and bracelets before getting your hands wet.
• Wear gloves in cold weather.
• Wear special gloves for tasks involving friction (e.g., gardening or carpentry).
• Avoid contact with irritants (such as detergents, solvents, hair dyes, or acidic foods).
• Avoid jewelry containing nickel or cobalt.

Mild to moderate dyshidrosis

Patients with mild to moderate dyshidrotic eczema who do not show significant improvement with the general measures listed above alone may benefit from high-potency topical corticosteroids (creams, gels, or ointments). The most commonly prescribed are Betamethasone, mometasone, clobetasol, triamcinolone, or fluticasone.

Topical corticosteroids should be applied twice daily for two to four weeks.

Compresses, potassium permanganate baths, or 2% boric water, two to three times daily, may be used prior to corticosteroid application, especially in patients with multiple and large blisters.

Despite the good response, long-term use of topical corticosteroids should be avoided due to their side effects, which include skin atrophy, stretch marks, and telangiectasia. In these cases, the alternative is to use ointments or creams containing tacrolimus 0.1% or pimecrolimus 1%.

Severe dyshidrosis

Severe forms should be treated with oral corticosteroids. Prednisone 40 to 60 mg daily for seven days, followed by prednisone 20 to 30 mg daily for another seven days, is the most appropriate regimen.

Refractory disease

Patients with frequent flares of dyshidrotic eczema may be treated with PUVA, which is a type of phototherapy that involves the use of a drug called psoralen to make the skin more sensitive to light, followed by exposure to UVA (ultraviolet A) light.

Diet

In some patients, recurrent dyshidrosis may be triggered by eating foods rich in cobalt or nickel.

It is, therefore, suggested that the patient take a dietary restriction test for 3 to 4 weeks, reducing the consumption of the foods listed below.

Foods rich in nickel:

• Canned foods.
• Food prepared with nickel-plated utensils.
• Herring.
• Fish and shellfish.
• Asparagus.
• Green beans.
• Mushrooms.
• Onions.
• Sweet corn.
• Spinach.
• Tomatoes.
• Peas.
• Whole-wheat flour.
• Pear.
• Chocolate.
• Baking Powder.

Cobalt-rich foods:

• Apricots.
• Green beans.
• Beer.
• Beetroot.
• Cabbage.
• Chocolate.
• Coffee.
• Liver.
• Walnuts.
• Scallops.
• Whole wheat flour.

Because it is challenging to restrict nickel and cobalt from the diet, as they are present in many foods, the success rate of the diet ends up being low, as few patients actually manage to reduce their intake of these metals.

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References

• Acute palmoplantar eczema (dyshidrotic eczema) – UpToDate.
• Acute and recurrent vesicular hand dermatitis – Dermatologic clinics of North America.
• Dyshidrotic eczema – American Academy of Dermatology.
• Dyshidrotic Eczema (Pompholyx) – Medscape.
• Wolff K, et al. Eczema/Dermatitis. In: Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology. 8th ed. New York, N.Y.: McGraw-Hill Education; 2017

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