Treating A Patient With Blisters And Papules On The Soles

      A 29-year-old Caucasian female patient presented in consultation in the foot and ankle clinic regarding a six-week history of erythematous vesicles and papules on the soles. She reported intense pruritus. Her primary care physician told her that she had a case of “athlete’s feet” and that she should use an over-the-counter (OTC) antifungal cream. After two weeks of treatment with antifungal cream, the patient had no improvement.       The "www.consultant360.com>primary care physician then prescribed a first-generation cephalosporin but after two weeks, the condition became worse. The patient stated that she had no known exposures to any new chemicals, paints, toxins, irritants or other potential allergens. She was taking birth control pills but denied taking any other medications, vitamins or supplements. No one else in her household or within her family had any similar conditions.

What The Exam Revealed

      Upon examination, the patient demonstrated small tense vesicular lesions and small papules on the lateral aspects of the digits of both feet and hands, and also on the plantar non-weightbearing surfaces of both feet. The vesicles did not involve the ankles or wrists, and there was little involvement of the dorsal acral surfaces. There were no targetoid lesions or other distinctive skin lesions. There were also no color changes or inflammation involving the eyes or ears. There were no tongue or oral lesions or discolorations. The patient’s vital signs were normal and there was no elevation of the oral temperature. The remaining portion of the physical examination was within normal limits and the patient had no other clinically significant skin conditions.

A Closer Look At Dyshidrotic Dermatitis

      The most likely diagnosis is dyshidrotic dermatitis/pompholyx. Fox first described dyshidrotic dermatitis in 1873. Characteristically, dyshidrotic dermatitis produces chronic foot and hand dermatitis, frequently with the formation of small vesicles on the outer aspects of the digits. Sometimes, clinicians refer to these vesicles as “tapioca pearls.” The term dyshidrotic eczema is a misnomer since abnormal sweat gland function is not implicated in this condition nor is it a specific eczematous disorder.       In 1876, Hutchinson described a much more severe form of the same condition, which he called “cheiropompholyx.” Several experts favor using the term “pompholyx” in reference to abrupt, primarily vesicular disease. Others continue to use the terms “dyshidrotic dermatitis,” “dyshidrotic eczema” and “pompholyx” interchangeably.       In general, hand and foot dermatitis is more common in women but dyshidrotic dermatitis may afflict men or women of any age equally. Previously, it has been said that dyshidrotic dermatitis is more prevalent among those with atopy and that over half of all patients with atopic dermatitis also have dyshidrotic dermatitis. Some authorities now dispute the relationship of atopy to dyshidrotic dermatitis.       Dyshidrotic dermatitis is a clinical diagnosis that clinicians may make via the history and clinical characteristics. It is characterized by symmetric vesicular eruptions on the soles, palms or lateral aspects of the digits, which eventually become dry and crusted. However, both surfaces of the palms and the soles may be involved simultaneously. Sharp demarcation at the wrists or ankles is common. Associated pruritus is intense in most reported cases. A clinical course of exacerbation and remission is common. This is sometimes associated with weather changes and, in other cases, may be associated with emotional stress.       It is usually not necessary to perform a biopsy in order to make the diagnosis. However, if one obtains a biopsy, the primary pathologic process identified is that of spongiotic dermatitis with an associated superficial perivascular lymphocytic infiltrate. The vesicular nature of the eruption is merely the phenotypic expression of severe spongiosis (epidermal edema) on acral skin with a thickened stratum corneum.       There are many reports and investigations regarding the relationship between dyshidrotic dermatitis and nickel allergy. Although some studies have demonstrated an increased rate of cutaneous allergy to nickel among those afflicted with dyshidrotic dermatitis, other studies have not demonstrated this association. Exacerbations of dyshidrotic dermatitis have been linked with nickel ingestion, even among those without cutaneous sensitivity to nickel. In fact, nickel-free diets reportedly improve dyshidrotic dermatitis in some patients.

A Guide To The Differential Diagnosis

      Vesicular tinea pedis. This is a common misdiagnosis but one may see this concurrently with dyshidrotic dermatitis. Dyshidrotic dermatitis occasionally resolves with the treatment of a tinea pedis infection and then relapses when the fungal infection recurs. This supports the existence of this reaction pattern. In regard to patients who have a vesicular reaction to intradermal trichophytin testing, less than one-third have experienced a resolution of pompholyx after treatment with antifungal agents. Examination of the lesions using potassium hydroxide wet mounts or periodic Acid Schiff reactions will be negative in most cases of isolated dyshidrotic dermatitis.       Palmoplantar pustular psoriasis. This chronic condition affects palms and soles, and may have periods of remission and exacerbation. It is characterized by sterile pustules. New pustules are usually yellow and the older pustules are brown. This is in contrast to dyshidrotic dermatitis in which tense vesicles may dry and crust over. Palmoplantar pustular psoriasis is strongly associated with cigarette smoking and is more common among females. This condition is difficult to treat effectively and one can diagnose it with a punch biopsy.       Classic erythema multiforme. This condition consists of targetoid eruptions affecting distal acral skin. It represents an immunologic reaction, most commonly to infection with herpes simplex. While central vesiculation may occur with erythema multiforme, targetoid lesions are lacking in this case of dyshidrotic dermatitis as is clinical evidence of an eruption of herpes simplex.       Bullous pemphigoid. This can involve the palms and soles, but the disorder is more common among the elderly, especially among those with multiple comorbidities. Such a diagnosis would be unlikely in an otherwise healthy young woman. Bullous pemphigoid would also probably involve additional areas of the body and is unlikely to be confined to the palms and soles.       Hand-foot-mouth disease. This is usually caused by Coxsackie A16 but can be caused by other Coxsackie viruses and Enterovirus 71. It is a self-limited disease with resultant acquired immunity. This disease is most common among young children but one may see this with some frequency up until puberty. Adults can get it but this is much less common. The early lesions are usually pink with a distinct mauve or purple border.       Irritant contact dermatitis. This is much more prevalent on the hands and is uncommon on the feet, especially in the non-weightbearing areas. Primary irritant dermatitis results from direct contact to the skin. It affects individuals exposed to specific irritants and generally produces discomfort immediately following exposure. Although irritant contact dermatitis is caused mostly by chemicals (such as acids, alkalis, solvents and oxidants), plants (such as hot peppers, garlic and tobacco) have also been implicated.       Insect bites and stings. These may involve both the feet and hands, and cause significant pruritus. Most bites are on the dorsum of the hand and foot rather than the palmoplantar surfaces. Scabies and fleas may bite and burrow into the skin of the fingers, toes, palms and soles. In most cases, the reactions from bites are much more erythematous and inflamed with fewer vesicles than one would find with dyshidrotic dermatitis.

Key Insights On The Prevention And Treatment Of Dyshidrotic Dermatitis

      Preventive measures include the identification of any aggravating factors such as secondary exposure to irritants. Wearing appropriate shoes or boots to prevent moisture from collecting in the shoes is important as is wearing wicking-material socks. Equally important is controlling localized hyperhidrosis. Decreasing emotional stress and stressful situations is also recommended.       In the initial stages of dyshidrotic dermatitis, when vesicles and blisters are present, foot soaks using weak solutions of Epsom salts (one cup in a basin of warm water) for 15 to 20 minutes twice a day will help to dry up blisters. A key component of treatment is using an emollient and a moisturizer, which the patient should apply together immediately after soaking or bathing. Effective moisturizers and emollients include products such as urea-based creams and lotions (Carmol or Keralac, Bradley Pharmaceuticals), petrolatum (Vaseline petroleum jelly) and mineral oil as well as products that contain ammonium lactate.       One should use topical corticosteroids as first-line treatment for dyshidrotic dermatitis. Use steroid creams when the skin is blistered or weeping, and use ointments for the chronic dry stage. Ointments are generally considered superior due to greater penetration and an absence of preservatives. When treating the thick skin of the palms and soles, utilizing potent or superpotent steroids is necessary, particularly early on, and then tapering to mid-potency agents as one achieves control. Clinicians may use occlusion initially to increase penetration of the topical agent but do not continue this for extended periods of time.       Topical immunomodulators, such as tacrolimus (Protopic, Astellas Pharma) and pimecrolimus (Elidel, Novartis), are reportedly successful in the treatment of mild to moderate recurrent dyshidrotic dermatitis. However, these agents may not be potent enough to treat severe cases.       Abrupt and severe eruptions, involving both feet and hands, classically referred to as pompholyx, may require oral corticosteroids. I like to use methylprednisolone 4 mg in a pre-measured tapering unit (Medrol Dosepak). Although one may often see dramatic improvement, use of oral steroids for prolonged therapy is limited by significant side effects.       While a nickel-free diet is still not consdered a primary treatment, it has been demonstrated to improve dyshidrotic dermatitis and decrease recurrences in some patients. However, a nickel-free diet is quite restrictive as no canned foods of any kind are permitted on such a diet and it requires a highly motivated patient to remain compliant.       Dr. Dockery is a Fellow of the American College of Foot and Ankle Surgeons, and a Fellow of the American Society of Podiatric Dermatology. He is board certified in foot and ankle surgery. He is the Chairman of the Board and Director of Scientific Affairs for Northwest Podiatric Foundation for Education and Research. Dr. Dockery is the author of Cutaneous Disorders of the Lower Extremity (Saunders, 1997) and Lower Extremity Soft Tissue & Cutaneous Plastic Surgery (Elsevier Science, 2006).
 

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