Palmoplantar Pustulosis

Synonyms: localised pustular psoriasis.

Palmoplantar pustulosis (PPP) is a chronic inflammatory skin condition, which typically presents as multiple sterile pustules on palms and soles (initially yellowish fading to brown macular pinpoint lesions). It is a relatively rare variant of psoriasis, but may occur in patients with other types of psoriasis.¹

The cause is unknown, but occurs much more commonly in smokers and ex-smokers. It may run in families and rarely occurs in childhood. Stress may also be a factor.²

• Infected eczema - less defined, white vesicles rather than pustules, swabs often grow staph. Acute pompholyx is an episodic form of eczema affecting the palms and soles with bulla formation, frequently becomes infected.
• Tinea pedis - commonly unilateral or asymmetrical erythema, scaling and pustules. Toe clefts and nails usually involved.
• Reiter's disease - gross palmar and plantar lesions may occur (keratoderma blenorrhagica) which are histologically indistinguishable from psoriasis. Also affects the mouth and penis.
• Acrodermatitis continua of Hallopeau (ACH): a rare indolent form of psoriasis with sterile pustular changes and dactylitis affecting the distal digits and nails.³

Evidence-based treatment for PPP is contentious. Various treatments are used but none is generally accepted as universally effective. A recent Cochrane Review highlighted methodological problems with the studies designed to differentiate between the efficacy of different approaches.⁵Within primary care:

• Encourage general measures:
  • Good footwear made from natural fibres
  • Avoidance of even minor trauma
  • Waterproof dressings over fissured areas
  • Rest affected area where possible
• Emollients are important:
  • Apply thick greasy emollients to soften skin and prevent fissures
  • Soak in warm water with emulsifying ointment
  • Use salicylic acid ointment or urea cream to peel dead skin
  • Wash with soap substitutes
• Potent topical steroid ointments eg clobetasone propionate may be used twice daily for limited periods. High potency steroids are required in order to penetrate the thick skin of the hands and feet. Occlusion with clingfilm or dressings can enhance penetration but should not be used for more than 5 days in a row.
• Coal tar is messy but can be applied directly, often mixed into an ointment base.
• Calcipotriol can be helpful, apply twice a day and do not cover.

Primarily for help with diagnosis and treatment, or if symptoms are particularly disabling.
Palms and soles are difficult sites to treat and palmar pustular psoriasis can be resistant to treatment so specialist advice may be required.
Further treatment options dermatologists can use include:

• PUVA to hands and feet which can give good results.⁶
• Acitretin (systemic retinoid)
• Methotrexate

• Pain from lesions and associated fissuring may be significant.
• Walking and standing for long periods can exacerbate lesions on soles of feet.
• Manual activity can be uncomfortable if hands affected.
• Occupational and functional disability secondary to above.

The condition tends to be chronic and poorly responsive to treatment.