What other topical options are available for a patient with psoriasis who has not responded to Enstilar (calcipotriene and betamethasone dipropionate) and has brittle diabetes?

Alternative Topical Options for Psoriasis Unresponsive to Enstilar in a Patient with Brittle Diabetes

For a patient with psoriasis who has failed Enstilar and has brittle diabetes, the best alternative topical options are coal tar preparations (starting at 0.5-1.0% crude coal tar in petroleum jelly, increasing to 10% as tolerated) or dithranol/anthralin (starting at 0.1-0.25%, doubling concentrations as tolerated), as these agents are extremely safe, have no systemic effects on glucose control, and avoid the metabolic complications associated with continued high-potency corticosteroid use. 1

Primary Alternative Topical Agents

Coal Tar Preparations

• Coal tar is extremely safe and can be used as either refined products or crude extracts such as crude coal tar in petroleum jelly. 1
• Start with concentrations of 0.5-1.0% crude coal tar in petroleum jelly and increase the concentration every few days to a maximum of 10%. 1
• Cruder tar extracts are messier to use but are generally considered much more effective than refined products like coal tar solution. 1
• Coal tar has no known effects on glucose metabolism, blood pressure, or renal function—making it ideal for patients with brittle diabetes. 1

Dithranol (Anthralin)

• Start treatment at a concentration between 0.1% and 0.25% and increase in doubling concentrations as the response allows. 1
• Use the "short contact mode" where the preparation is left on the skin for only 15 to 45 minutes every 24 hours, which can be of great benefit. 1
• Great care should be taken with dithranol on sensitive body sites such as the face, flexures, and genitalia. 1
• Patients must be adequately counseled about side effects including irritancy and staining of skin and clothes. 1

Alternative Topical Corticosteroid Formulations

Tazarotene (Retinoid Option)

• Tazarotene 0.1% cream applied once daily in the evening is an effective alternative that works through a different mechanism than vitamin D analogues. 2
• In controlled trials, tazarotene demonstrated significant reductions in plaque elevation (mean change -0.83 to -1.08), scaling (-0.75 to -0.84), and erythema (-0.49 to -0.57) compared to vehicle. 2
• Apply only to psoriasis lesions, avoiding uninvolved skin, and patients may use moisturizers or emollients at least 1 hour before application. 2
• Critical contraindication: Tazarotene is pregnancy category X and absolutely contraindicated in females of reproductive potential without effective contraception. 2

Clobetasol Propionate (Alternative Corticosteroid Formulation)

• If switching corticosteroid vehicles improves adherence, clobetasol propionate 0.05% in foam, spray, or lotion formulations show similar efficacy (17-80% success rates) to ointment with better patient acceptance. 3, 4
• However, given the patient's brittle diabetes, prolonged or extensive use of any superpotent corticosteroid should be avoided due to potential systemic absorption and effects on glucose control. 1

Critical Monitoring Requirements for Brittle Diabetes

• There should be regular clinical review with no unsupervised repeat prescriptions of any corticosteroid preparations. 1
• No more than 100 g of a moderately potent (BNF grade III) corticosteroid preparation should be applied each month. 1
• There should be periods each year when alternative non-corticosteroid treatment is employed to minimize systemic corticosteroid exposure. 1

Medications to Avoid in This Patient

• Avoid beta-blockers and NSAIDs as these may precipitate or worsen psoriasis. 1
• Never use systemic corticosteroids as they can precipitate severe psoriasis flares upon discontinuation and will destabilize glucose control. 5
• Lithium, chloroquine, and mepacrine may be associated with severe, even life-threatening, deterioration of psoriasis. 1

Combination Therapy Approach

• Patients receiving any topical agent should be encouraged to also apply emollients, as effective topical modalities may provide a dose-sparing effect. 1
• If using any residual corticosteroid therapy, combining with calcipotriol (vitamin D analogue) increases both speed and level of response. 1
• The combination of calcipotriene and betamethasone has been shown to achieve clearing or 90% PASI reduction in 50% of patients even at very low corticosteroid dosages (2 mg/kg/day ciclosporin equivalent). 1

When to Consider Systemic Therapy

• For patients who fail to respond to alternative topical agents, it is worth trying multiple different topical agents before considering more aggressive systemic management, as some patients who fail one topical agent will respond to another for poorly understood reasons. 1
• If topical therapy remains inadequate, TNF-alpha inhibitors (adalimumab, etanercept, or infliximab) are the preferred next-line systemic therapy due to their lack of drug interactions, no deleterious effects on renal function or blood pressure, and no significant impact on glucose control when diabetes is well-managed. 5

Common Pitfalls to Avoid

• Do not continue escalating corticosteroid potency indefinitely—this increases systemic absorption risk and can worsen glucose control in diabetic patients. 1, 5
• Do not dismiss coal tar or dithranol as "old-fashioned"—these remain highly effective, safe options with no metabolic effects. 1
• Ensure patients understand that coal tar and dithranol require patience and proper application technique, including the short-contact method for dithranol. 1