Keratoderma

Definition

• Keratoderma (palmoplantar keratosis) refers to thickening of the skin (hyperkeratosis) on the palms and/or soles. It can be inherited (genodermatoses) or acquired due to various conditions (psoriasis, eczema, environmental factors).

Types

1. Diffuse

   • Widespread thickening across most of the palms/soles

2. Focal

   • Localised hyperkeratotic plaques at pressure areas (e.g. weight-bearing parts of soles, friction points on palms)

3. Punctate

   • Multiple small bumps or “dots” of thickened skin on the palms/soles

Non-Transgradient vs Transgradient

• Non-Transgradient: Limited to palms/soles, spares the dorsal surfaces

• Transgradient: Extends beyond the palmoplantar margins onto the dorsum of hands/feet

Management

General Measures

• Emollients: Moisturise to soften thick skin, reduce cracking

  • Choose products with urea or other humectants for better penetration

• Avoid triggers: Excess friction, repetitive trauma

Keratolytics

• Salicylic Acid (6%) or Propylene Glycol (70%) solutions/ointments help dissolve thick keratin

• Apply under occlusion at night for deeper penetration

Topical Retinoids

• Tretinoin or adapalene creams can reduce hyperkeratosis over time

• Start slowly to minimise irritation (e.g. alternate nights, gradually increase frequency)

Topical Vitamin D Analogues

• Calcipotriol: Softens keratotic plaques, may be used alone or in combination with other topicals

Systemic Retinoids

• Acitretin for severe or refractory palmoplantar keratoderma

  • Requires monitoring for hepatic function and hyperlipidaemia

  • Teratogenic → strict contraception for women of childbearing potential

Notes

• Some keratodermas are part of genetic syndromes (e.g., pachyonychia congenita, palmoplantar keratoderma of various inheritance patterns).

• Assess for underlying diseases (psoriasis, eczema, tinea, or systemic conditions) if the keratoderma is new or atypical.

• Referral to dermatology if uncertain diagnosis or severe, unresponsive to standard measures.