Acquired keratoderma

What is acquired keratoderma?

Acquired keratoderma refers to non-inherited forms of palmoplantar keratoderma and presents with excessive epidermal thickening of the palms and soles. It can arise from various causes, including other skin conditions.

This condition is also called acquired palmoplantar keratoderma.

Who gets acquired keratoderma?

Acquired keratoderma typically affects patients in adulthood and does not involve a family history. However, it may occur secondary to a hereditary skin condition.

Acquired keratoderma is uncommon, and its exact incidence and prevalence are unknown. However, it is more common than hereditary forms of palmoplantar keratoderma.

What causes acquired keratoderma?

• Chemical exposure eg, arsenic, chlorinated hydrocarbons
• Dermatoses eg, eczema, psoriasis, lichen nitidus, lichen planus, pityriasis rubra pilaris
• Drug exposure eg, venlafaxine, lithium, hydroxyurea, imatinib, capecitabine, gold, fluorouracil
• Infection eg, crusted scabies, fungal infection (especially Trichophyton rubrum), human immunodeficiency virus, human papillomavirus, leprosy, syphilis, Reiter disease, tuberculosis
• Internal malignancy eg, mycosis fungoides, breast/lung/gastric/colon/bladder cancer
• Keratoderma climactericum
• Malnutrition
• Systemic disease eg, myxoedema, diabetes mellitus, lupus erythematosus, chronic lymphoedema
• Others: aquagenic, mechanical stimulation
• Idiopathic

Keratoderma of the palms due to psoriasis 

Lichen planus on the palms producing a keratoderma (BLP-patient1)

Crusted scabies causing a keratoderma 

Thickened dry skin on the heels arising at the menopause-keratoderma climactericum 

A keratoderma due to dermatophyte infection 

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What are the clinical features of acquired keratoderma?

Features are typically confined to the palms and/or soles and include:

• Thickened skin
• Hard, yellow, and flaky skin
• Fissures
• Circumferential erythematous border
• Possible hyperhidrosis
• Features may be diffuse (involve most of the palm/sole) or focal (localised to pressure areas).

Features in association with malignancy:

• Rapid progression of skin symptoms with keratoderma, acanthosis nigricans, and mucosal involvement; may be associated with gastrointestinal, lung, uterus, ovarian, or urinary tract malignancy
• Generalised psoriasiform plaques with painful paronychia, nail changes, and palmoplantar keratoderma with central clearing; seen in acrokeratosis paraneoplastica.

What are the complications of acquired keratoderma?

• Pain and/or fissuring on movement
• Tight bands around digits that produce an ainhum
• Maceration between toes and fingers
• Reduced sensation on affected areas
• Hand and foot contractures
• Foot odour
• Bacterial infection
• Fungal infection eg, tinea manuum, tinea pedis
• Psychological distress

How is acquired keratoderma diagnosed?

Acquired keratoderma is a clinical diagnosis based on a detailed medical history and physical examination. If hereditary palmoplantar keratoderma is suspected, genetic consultation and genetic screening should be considered.

Underlying causes should be investigated and treated. Blood tests, skin biopsy, mycology, bacterial testing, and imaging studies should be considered on a case-by-case basis. Investigations for malignancy may include serum tumour markers and PET/CT imaging studies.

Key histological features include:

• Compact hyperkeratosis
• Parakeratosis
• Acanthosis
• Hypergranulosis
• Superficial dermal and perivascular infiltrate.

What is the differential diagnosis for acquired keratoderma?

• Plantar warts
• Callosities
• Tripe palms (acanthosis palmaris) — associated with internal malignancy

What is the treatment for acquired keratoderma?

Acquired keratoderma is best managed by treating any underlying condition(s).
If idiopathic, management of acquired keratoderma focuses on symptom relief through:

• Softening and reducing the thickness of affected skin
• Reducing pain and discomfort
• Improving the overall function of the hands and feet.

However, these interventions typically only provide temporary relief, recurrence is common upon discontinuation, and treatment guidance is limited by the rare and variable nature of this condition.

Non-pharmacological treatments

• Regular soaking of affected areas to loosen scale
• Gentle mechanical debridement with tools such as pumice stones or callus files
• Podiatry services to assist with scale removal
• Consideration of orthotics to offload affected skin
• Regular use of emollients
• Physical therapy to help mobilise joint or tendon contractures, where indicated

Pharmacological treatments

Topical keratolytics

A combination of multiple topical keratolytic agents in a cream or ointment base may be used, optionally under occlusion.

• Urea 40%
• Salicylic acid 5% to 10%
• Propylene glycol 20% to 70%
• Lactic acid 10% in aqueous cream
• Combination therapy with 10% urea and 5% lactic acid in aqueous cream

Topical retinoids

• Tretinoin 0.025% to 0.1% cream
• Tazarotene 0.05% or 0.1% cream

Systemic retinoids

• Acitretin, isotretinoin, etretinate, alitretinoin

Potent topical corticosteroids

• Clobetasol propionate 0.05%

Phototherapy

• Psoralen plus ultraviolet A (PUVA) therapy may be considered for cases associated with inflammatory conditions such as psoriasis or eczema.

Surgical interventions

• Surgical release of contractures and bands
• Skin debridement
• Excision of hyperkeratotic skin with subsequent skin grafting — typically reserved for severe cases

What is the outcome for acquired keratoderma?

Acquired keratoderma is a chronic condition that typically requires ongoing management to achieve symptom control. Symptoms may resolve with the treatment of any underlying condition(s).

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