Can Shingles Trigger Psoriasis?
Yes, shingles can trigger psoriasis through the Koebner phenomenon, where new psoriatic lesions develop at sites of skin trauma or inflammation, including areas affected by active, healing, or healed herpes zoster lesions. 1
Evidence for Shingles-Induced Psoriasis
The most compelling evidence comes from a documented case report demonstrating that psoriatic Koebner phenomenon can occur not only at sites of healed shingles, but also at areas of actively developing shingles lesions 1. In this case, a 30-year-old man with scalp psoriasis developed characteristic psoriatic plaques with silver scales and bleeding points (Auspitz sign) in the exact dermatomal distribution where herpes zoster vesicles were erupting on his chest wall 1.
- The psoriatic lesions appeared in the dermatome distributed on the right chest wall where the herpes zoster lesions were actively developing 1
- After treatment, when psoriasis recurred a year later, it affected only the scalp and the previous shingles site, confirming this was true Koebner phenomenon rather than coincidental psoriasis 1
- Approximately 25% of psoriatic patients are susceptible to developing Koebner phenomenon after various skin injuries 1
Clinical Implications and Mechanism
The relationship between varicella-zoster virus and psoriasis extends beyond just the Koebner phenomenon:
- Vaccination can also trigger psoriasis: A 52-year-old male with longstanding plaque-type psoriasis developed acute guttate psoriasis flare 2 weeks after receiving the recombinant herpes zoster vaccine 2
- The inflammatory cascade triggered by VZV reactivation or vaccination appears sufficient to precipitate psoriatic lesions in susceptible individuals 2
Important Caveats for Psoriasis Patients
Patients with psoriasis on systemic immunosuppression face increased herpes zoster risk, creating a bidirectional concern 3:
- Tofacitinib carries strong evidence (level 1) for increased HZ risk 3
- Systemic corticosteroids carry strong evidence (level 1) for increased HZ risk 3
- Combination therapy with biologics and conventional DMARDs carries weak evidence (level 2a) for increased HZ risk 3
- Biologic monotherapy does not appear to increase HZ risk 3
Vaccination Recommendations for Psoriasis Patients
The recombinant zoster vaccine (Shingrix) is recommended for all psoriasis and psoriatic arthritis patients >50 years old, and for younger patients on high-risk therapies (tofacitinib, systemic steroids, or combination systemic treatment) 3. However, clinicians should counsel patients about the small risk of psoriasis exacerbation following vaccination 2, weighing this against the substantial benefit of preventing herpes zoster and its potential to trigger Koebner phenomenon 1, 3.
The key clinical takeaway: Monitor psoriasis patients who develop shingles closely for new psoriatic lesions in the affected dermatome, as this represents a treatable complication that responds to standard anti-psoriatic therapies 1.