Keratolysis exfoliativa
Keratolysis exfoliativa also known as exfoliative keratolysis, dyshidrosis lamellosa sicca or recurrent focal palmar peeling, is a common palmoplantar dermatosis in which there is focal peeling of the palms and less often the soles. Keratolysis exfoliativa is characterized by air‐filled blisters on an erythematous base, which results in lamellar peeling with hallmark superficial collarettes of scale 1. Patients typically complain of asymptomatic peeling on the palms and occasionally the soles that recurs every few weeks. Keratolysis exfoliativa most commonly occurs in young adults and is typically worse in the summer months or with warm weather.
Some patients may find that this condition is exacerbated by chemical or physical irritants such as water, soap, and detergents. Others may associate it with hyperhidrosis. Most patients deny any itching, but may rarely complain of slight tenderness. This is likely a common condition that rarely presents to physicians because it is largely asymptomatic.
It has been regarded as a subtype of dyshidrotic eczema, a fungal infection or a dermatophytid reaction. Keratolysis exfoliativa may also resemble acral peeling skin syndrome and localized epidermolysis bullosa simplex. Although keratolysis exfoliativa is a common disorder, it is a rarely reported and is an under‐recognized dermatosis.
Keratolysis exfoliativa generally presents in young active adults. Some individuals have a family history of the disorder.
Recent histopathologic and molecular studies have linked keratolysis exfoliativa to premature corneo-desmosomal disruption. Acitretin has previously been used to treat diseases of abnormal corneocyte desquamation, for example Netherton’s disease.
Figure 1. Keratolysis exfoliativa
Keratolysis exfoliativa causes
The cause of keratolysis exfoliativa is unknown. Microscopy reveals cleavage within the outside horny layer of skin, the stratum corneum. It is thought that for some reason the desmosomes on the corneocytes separate from each other prematurely. No genetic abnormality has been detected to date.
The symptoms are aggravated by exposure to irritants including water, soap, detergents and solvents.
Keratolysis exfoliativa symptoms
Keratolysis exfoliativa is more common during the summer months in about 50% of affected individuals. It may be more common in those with sweaty palms due to localised hyperhidrosis.
The first sign of keratolysis exfoliativa is one or more superficial air-filled blisters on the fingers or palms. The blisters burst to leave expanding collarettes of scale and circular or oval, tender, erythematous peeled areas. These peeled areas lack a normal barrier function and may become dry and cracked. However, they are not generally itchy.
Sometimes on the ends of the fingers, the split in the skin is deeper, in which case the skin feels hard and numb and takes longer to peel off. There can be multiple layers of peeling skin (lamellae).
Eventually normal skin forms, but frequently exfoliative keratolysis recurs within a few weeks.
Keratolysis exfoliativa diagnosis
Keratolysis exfoliativa is diagnosed clinically. Supportive investigations may be undertaken.
- Skin biopsy shows cleavage and partially degraded corneodesmosomes within the stratum corneum.
- Skin scrapings sent for laboratory tests for fungal infections are negative.
- Patch tests evaluating potential contact allergy are negative.
There is usually no need for further diagnostic testing, as keratolysis exfoliativa is typically a clinical diagnosis; however, in more difficult cases, a potassium hydroxide (KOH) scraping or fungal culture to rule out tinea should be negative and patch testing to rule out allergic contact dermatitis should also be negative.
Physical examination
On physical examination there are symmetrical, irregular circumscribed annular or circinate patches of superficial scaling on the palms and, less often, the soles (Figure 1). The scaling gradually extends peripherally, leaving an adherent collarette. Keratolysis exfoliativa is also characterized by a lack of inflammation.
Keratolysis exfoliativa differential diagnosis
Keratolysis exfoliativa is distinct from the following conditions:
- Various forms of hand dermatitis including contact dermatitis
- Pompholyx or dyshidrotic eczema, an itchy form of eczema in which there are small fluid-filled blisters.
- Palmoplantar psoriasis or palmoplantar pustulosis, in which there are scaly patches
- Tinea manuum, but scrapings for fungal culture are negative in keratolysis exfoliativa
- Keratolytic winter erythema, a rare inherited condition characterized by red peeling hands and feet
- Palmoplantar keratoderma
- Localized epidermolysis bullosa simplex, in which blistering occurs
- Circumscribed palmar hypokeratosis
- Tinea (typically seen with associated changes in the fingernails or toenails, occasionally pruritic, does not wax and wane, positive fungal scraping or culture, and responds to treatment with antifungal agents)
Keratolysis exfoliativa treatment
Keratolysis exfoliativa does not improve with topical steroids, unlike hand dermatitis.
The following may be helpful:
- Protection from irritants, wear gloves, good moisturization.
- Treat hyperhidrosis if present. Emollient hand creams (keratolytic creams) especially those containing urea, lactic acid, salicyclic acid, ammonium lactate or silicone
- Acitretin
- Photochemotherapy.
Any exacerbating factors should be controlled. This should include protecting the hands from any physical or chemical irritants and encouraging the patient to wear gloves when possible. Educating the patient on the benign nature of this condition is imperative, as often the patient merely wants a diagnosis and does not desire any further treatment. Inquire about any history of atopic dermatitis.
If there is a component of primary hyperhidrosis, attempt to treat it with topical medication. Drysol, applied to dry skin at bedtime, or oral glycopyrrolate, starting at a dosage of 1mg by mouth 2-3 times daily, may be helpful.
Aggressive moisturization is one of the most important treatments and is often the safest and most effective treatment modality.
Keratolytic creams containing urea, lactic acid, ammonium lactate, or salicylic acid have been the most beneficial treatment for the majority of patients. Examples of these include urea 20% or 40% cream, ammonium lactate 12% cream, salicyclic acid 6% cream, and lactic acid 12% cream. Any one of these can be applied up to twice daily.
A trial of potent (betamethasone dipropionate 0.05% or equivalent) or ultrapotent (clobetasol 0.05% or equivalent) topical corticosteroid applied twice daily for no more than 2 weeks could be attempted; however, these are typically not found to be very beneficial as this disease is characterized by a lack of inflammation.
There are some texts that mention the use of photochemotherapy with hand/foot psoralen and ultraviolet A light (PUVA [psoralen and ultraviolet A light]) for severe cases. This should be reserved for severe or symptomatic patients, as otherwise the risks outweigh the benefits. Patients should be aware that this treatment is purely anecdotal and data to support its benefit is lacking.
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