What is the best approach to manage localized pustular psoriasis in a patient with plaque psoriasis who has recently undergone steroid (corticosteroid) treatment?

Management of Localized Pustular Psoriasis Following Recent Steroid Treatment

Immediately discontinue or taper the topical corticosteroids that were recently used, as abrupt withdrawal can trigger or worsen pustular transformation of plaque psoriasis, then initiate moderate-potency topical corticosteroids (British National Formulary grade III) for symptomatic relief of the localized pustular lesions. 1, 2

Critical First Step: Address the Steroid Withdrawal Risk

The development of localized pustular psoriasis in a patient with plaque psoriasis who recently received steroid treatment raises immediate concern for steroid-induced pustular transformation. Abrupt withdrawal of topical corticosteroids can cause rebound effects, potentially worsening pustular psoriasis. 1 The FDA drug label for clobetasol specifically warns that "treatment (or withdrawal of treatment) of psoriasis with corticosteroids is thought to have exacerbated the disease or provoked the pustular form of the disease." 3

Recommended Treatment Approach

For Localized Pustular Psoriasis of Palms and Soles

• Apply a moderately potent topical corticosteroid (British National Formulary grade III) for symptomatic relief, as this is the established first-line approach for localized pustular psoriasis. 2
• Triamcinolone acetonide 0.1% applied twice daily represents an appropriate moderate-potency option for initial management. 4
• Limit treatment duration to 4 weeks initially, with careful monitoring for adverse effects including skin atrophy, striae, folliculitis, telangiectasia, and purpura. 2, 1

Alternative and Adjunctive Therapies

• Topical coal tar (0.5-1.0% crude coal tar in petroleum jelly, increasing to maximum 10%) can provide benefit as a steroid-sparing agent, though it is messier to use. 2
• Vitamin D analogs (calcipotriene, calcitriol) should be considered as steroid-sparing alternatives for localized pustular psoriasis. 1
• Topical calcineurin inhibitors (tacrolimus, pimecrolimus) are safer alternatives for sensitive areas and avoid the atrophy risk of long-term corticosteroid use. 1, 4

Monitoring Requirements

• Regular clinical review is mandatory with no unsupervised repeat prescriptions. 2
• No more than 100g of a moderately potent (grade III) preparation should be applied each month. 2
• There should be periods each year when alternative treatment is employed to minimize cumulative steroid exposure. 2

Important Clinical Pitfalls

Avoid These Common Errors

• Do not use ultrahigh-potency (class 1) corticosteroids on palms and soles for pustular psoriasis without dermatology supervision, as the risk-benefit ratio favors moderate potency for this specific variant. 2
• Never abruptly stop all corticosteroid therapy if the patient is currently using potent steroids, as this can precipitate generalized pustular transformation. 2, 1
• Avoid applying corticosteroids to areas with active pustulation without addressing the underlying trigger (steroid withdrawal). 3

When to Escalate Beyond Topical Therapy

If the localized pustular psoriasis proves treatment-resistant to moderate-potency topical corticosteroids after 4 weeks, consider systemic therapy with etretinate (starting at 0.75 mg/kg/day), as this has shown success in localized pustular psoriasis of palms and soles. 2

For acropustulosis (acrodermatitis continua of Hallopeau) affecting terminal phalanges with nail destruction, TNF antagonists (etanercept, infliximab, adalimumab) have shown significant benefit in at least 10 case reports and should be considered if quality of life is severely impacted. 2

Critical Warning About TNF Antagonists

Do NOT use TNF antagonists for chronic palmoplantar pustulosis, as this condition shows almost complete lack of benefit from these agents and may paradoxically worsen. A pilot study found no benefit of etanercept 50mg twice weekly for 12 weeks over placebo. 2

Distinguishing Localized Variants

The clinical distinction matters for treatment selection:

• Chronic palmoplantar pustulosis (associated with plaque psoriasis in ~20% of cases) responds poorly to TNF antagonists and should be managed with topical corticosteroids and retinoids. 2
• Acropustulosis of Hallopeau (affecting terminal phalanges with destructive arthritis risk) may benefit from TNF antagonists if conventional therapy fails. 2

Successful Case Management Example

One documented case successfully managed ustekinumab-induced pustular psoriasis by adding topical corticosteroids without discontinuing the biologic therapy, achieving complete remission of pustular lesions while maintaining control of underlying plaque psoriasis. 5 This demonstrates that topical corticosteroids can effectively manage localized pustular flares as adjunctive therapy when systemic treatment for plaque psoriasis must continue.