Management of Localized Pustular Psoriasis

First-Line Topical Therapy

The British National Formulary recommends moderately potent topical corticosteroids (grade III) as first-line therapy for localized pustular psoriasis of the palms and soles, with topical coal tar and dithranol as alternative options, while avoiding systemic corticosteroids due to risk of disease exacerbation 1, 2
Topical coal tar (starting at 0.5-1.0% crude coal tar in petroleum jelly, increasing to maximum 10%) provides some benefit, with cruder extracts being more effective than refined products 2
Topical dithranol (anthralin) may be beneficial, starting at 0.1-0.25% concentration and increasing in doubling concentrations as tolerated, though great care is needed on sensitive areas 2

The National Health Service recommends considering systemic agents in refractory cases of localized pustular psoriasis, as treatment is generally unsatisfactory with topicals alone 1, 2
Acitretin (0.1-1 mg/kg/day) has achieved some success in localized pustular psoriasis and is particularly effective for pustular variants 1, 3
PUVA (psoralens plus ultraviolet A) is considered the systemic treatment of first choice with the least toxicity among systemic options 3
Infliximab 5 mg/kg demonstrates rapid efficacy in severe cases, though it is primarily indicated for generalized pustular psoriasis 3, 4

All systemic agents are absolutely contraindicated in pregnancy and require mandatory contraception counseling before initiation 3, 5
Acitretin is contraindicated in women planning pregnancy within 2 years of stopping treatment 3, 5
Cyclosporine is contraindicated with abnormal renal function or uncontrolled hypertension 3, 5
Methotrexate is contraindicated in pregnancy, breastfeeding, significant hepatic damage, and blood disorders 3, 5

PUVA requires starting dose determination after estimation of minimum phototoxic dose at 72 hours, with 70% of this dose as the initial treatment 1
Commercially available sunbeds (emitting ultraviolet A) are rarely effective and not recommended due to side effects including premature skin aging 1

Systemic corticosteroids should never be used as primary therapy for pustular psoriasis, as they precipitate severe disease flares upon discontinuation and can trigger generalized pustular psoriasis or erythrodermic psoriasis 3, 5
TNF antagonists (infliximab, etanercept, adalimumab) should be avoided in chronic palmoplantar pustulosis, as they may exacerbate this specific condition 3, 5
Lithium, chloroquine, and mepacrine may cause severe deterioration of pustular psoriasis 4, 5
Beta-blockers and NSAIDs may worsen psoriasis in some patients 4

For patients on systemic therapy, pretreatment assessment must include history, examination, full blood count, liver function tests, and serum creatinine 5
Regular ongoing monitoring requirements depend on the specific agent, including liver function tests and fasting serum lipids for acitretin, blood pressure and serum creatinine monitoring for cyclosporine, and full blood count and liver function tests regularly for methotrexate 5