Which medications are known to trigger or worsen psoriasis, and what precautions should be taken when prescribing them?

Drugs That Can Trigger or Worsen Psoriasis

Lithium, chloroquine, and mepacrine are associated with severe, even life-threatening deterioration of psoriasis and should be avoided or used with extreme caution in patients with this condition. 1

High-Risk Medications (Strong Evidence)

Antimalarials

• Chloroquine and mepacrine can cause severe, potentially life-threatening psoriasis exacerbations 1
• These agents should be considered contraindicated in patients with known psoriasis 2

Lithium

• Strongly associated with psoriasis induction and exacerbation 1, 2
• Can trigger disease in predisposed individuals or worsen existing psoriasis 3, 4
• Represents one of the most well-documented drug-psoriasis associations 2

Beta-Blockers

• Documented to precipitate or worsen psoriasis in susceptible patients 1, 2
• Strong evidence supports this association across multiple studies 3, 4
• Should be avoided when alternative antihypertensive agents are available 2

Systemic Corticosteroids

• Abrupt withdrawal is a critical trigger for erythrodermic transformation 5, 6
• 50% of dermatologists and 29% of rheumatologists have observed psoriasis flare-ups following oral corticosteroid treatment 6
• Approximately 10% of specialists have observed flare-ups after intramuscular or intra-articular corticosteroid administration 6
• Never discontinue systemic corticosteroids abruptly in psoriasis patients 5

Moderate-Risk Medications (Considerable Evidence)

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)

• Can precipitate or worsen psoriasis in some patients 1, 2
• Naproxen (25.5%) and diclofenac (14.7%) were the most frequently prescribed potentially inappropriate medications in psoriasis patients 7
• The association is well-documented but not universal 3

Interferons

• Strong association with psoriasis induction 2
• Can trigger disease even in patients without prior psoriasis history 2

Terbinafine

• Documented association with psoriasis exacerbation 2
• Should be used cautiously in patients with known psoriasis 2

Imiquimod

• Can induce or worsen psoriatic lesions 2
• Topical application may trigger localized or generalized flares 2

Emerging Concerns (Recent Evidence)

Targeted Immunotherapies

• TNF-alpha antagonists can paradoxically induce psoriasis or psoriasiform eruptions 2, 8
• Anti-PD-1 immune checkpoint inhibitors (used in oncology) have been associated with new-onset psoriasis 2
• IL-4/13 blockade in atopic dermatitis may trigger psoriasis through shift toward IL-17-driven inflammation 8

Additional Medications with Reported Associations

Less Common but Documented Triggers

• Gold salts: established association 4
• Tetracyclines: documented cases 3
• Gemfibrozil: observed exacerbations 4
• Digoxin: reported associations 4
• Clonidine: documented cases 4
• Iodine: can trigger flares 4

Clinical Management Approach

When Drug-Induced Psoriasis is Suspected

1. Assess temporal relationship: Evaluate the latency period between drug initiation and psoriasis onset, recognizing that this can be significantly prolonged for some medications 2

2. Apply Naranjo scale: Use the Naranjo adverse drug reaction probability scale as a practical tool to differentiate drug-related from spontaneous psoriasis 2

3. First-line intervention: Discontinue and replace the offending drug when clinically feasible 2

4. Anticipate persistence: Drug-induced lesions may persist after medication withdrawal, requiring additional treatment 2

5. Treat according to standard guidelines: Use conventional psoriasis therapies including topical steroids, vitamin D analogs, phototherapy, systemic agents (acitretin, methotrexate, fumaric acid esters), or biologics 2

Critical Precautions for Prescribers

High-Risk Patient Populations

• Patients with comorbidities requiring multiple medications have increased risk: those with chronic conditions (OR 1.94,95% CI 1.566-2.402) and coronary heart disease (OR 6.25,95% CI 1.895-20.645) are more likely to receive potentially inappropriate prescriptions 7

Documentation Requirements

• 55.3% of psoriasis patients receive at least one drug associated with worsening dermatological lesions, highlighting the need for careful medication review 7
• Only 44% of physicians take precautions when prescribing systemic corticosteroids to psoriasis patients, indicating a significant gap in clinical practice 6

Common Pitfall

The clinical and histopathological features of drug-provoked psoriasis may be indistinguishable from classical psoriasis, making recognition challenging 2. Maintain high index of suspicion when new medications are introduced or when stable psoriasis suddenly worsens 3.