What is the appropriate treatment for ulcerated plaques with raised, rolled edges in a patient with psoriasis?

Critical Clinical Alert: This is NOT Typical Psoriasis

Ulcerated plaques with raised, rolled edges in a psoriasis patient should immediately raise suspicion for methotrexate toxicity, squamous cell carcinoma, or another serious pathology—NOT standard psoriatic disease requiring routine treatment escalation.

Immediate Diagnostic Imperative

The description of "rolled raised edges and wounds" is a red flag that demands urgent evaluation before any treatment modification:

Key Differential Diagnoses to Rule Out:

1. Methotrexate Toxicity

• Methotrexate can cause cutaneous ulcerations specifically on psoriatic plaques 1
• This presents as ulcerated and necrotic lesions on existing psoriatic plaques
• Critical question: Is the patient currently on methotrexate? What is their dosing schedule?
• Accidental overdosing (e.g., daily instead of weekly dosing) causes rapid ulceration with mouth erosions and hair loss 1

2. Squamous Cell Carcinoma

• Rolled edges are a classic morphologic feature of SCC, not psoriasis
• Chronic inflammatory skin diseases like psoriasis increase SCC risk
• Long-term immunosuppression (cyclosporine, biologics) further elevates this risk 2

3. Other Malignancy or Atypical Infection

• Ulcerated plaques with atypical morphology warrant biopsy

Mandatory First Steps

Before initiating or modifying any psoriasis therapy:

1. Obtain tissue diagnosis: Perform punch or excisional biopsy of the ulcerated area with rolled edges
2. Review medication history: Confirm methotrexate dosing if applicable (daily vs. weekly administration)
3. Check complete blood count: Methotrexate toxicity causes pancytopenia
4. Assess for systemic toxicity: Mucositis, hepatotoxicity, renal dysfunction

If Methotrexate Toxicity is Confirmed

• Immediately discontinue methotrexate 3
• Lesions typically heal rapidly within 2 weeks after cessation 1
• Consider leucovorin rescue if severe toxicity
• Methotrexate is contraindicated in patients with significant thrombocytopenia, leukopenia, or anemia 3

If Malignancy is Ruled Out and This Represents Severe Psoriasis

Only after excluding the above pathologies should you consider this severe, treatment-resistant psoriasis requiring systemic therapy:

Highest Efficacy Biologic Options (in rank order):

For achieving complete or near-complete clearance (PASI 90):

1. Infliximab (moderate-certainty evidence) 4, 5

   • 5 mg/kg IV at weeks 0,2,6, then every 8 weeks 2
   • Can increase frequency to every 4 weeks or dose to 10 mg/kg for refractory disease 2
   • Strongly consider adding methotrexate to reduce immunogenicity and antibody formation 2

2. Bimekizumab (high-certainty evidence) 4, 5

   • Anti-IL-17A/F agent with highest certainty evidence

3. Ixekizumab (moderate-certainty evidence) 4, 5

   • Anti-IL-17A agent

4. Risankizumab (moderate-certainty evidence) 4, 5

   • Anti-IL-23p19 agent with durable responses

Combination Therapy to Augment Efficacy:

All biologics can be combined with high-potency topical corticosteroids with or without vitamin D analogues to enhance efficacy 2. This combination has Grade B recommendation strength for infliximab and adalimumab 2.

Critical Pitfalls to Avoid

1. Never assume ulcerated plaques with rolled edges are "just psoriasis"—this morphology is atypical and demands histologic confirmation
2. Never continue methotrexate if toxicity is suspected—the drug must be stopped immediately as it is contraindicated with significant cytopenias 3
3. Do not empirically escalate immunosuppression without ruling out malignancy or infection in atypical presentations
4. If using infliximab, do not allow intervals >8 weeks between infusions, as this increases antibody formation and infusion reactions 2

Bottom Line

This clinical presentation is NOT routine psoriasis until proven otherwise. Biopsy the lesions immediately, review all medications (especially methotrexate dosing), and rule out malignancy before considering this a treatment failure requiring biologic escalation. If methotrexate toxicity is identified, discontinuation alone typically results in rapid healing within 2 weeks 1.