What are the treatment options for managing guttate psoriasis?

Guttate Psoriasis Management

For guttate psoriasis, start with topical corticosteroids (moderately potent, grade III) combined with narrowband UVB phototherapy as first-line treatment, while screening for and treating any underlying streptococcal infection. 1, 2

Initial Workup

• Screen all patients for streptococcal infection with throat culture or rapid streptococcal antigen test, as guttate psoriasis is closely associated with preceding streptococcal pharyngitis occurring 3-4 weeks prior 1
• Consider anti-streptolysin O (ASO) titers if recent infection is suspected 1
• Avoid confusing the guttate eruption with antibiotic allergy—the rash typically appears 3-4 weeks after the streptococcal infection, not immediately 1

Treatment Algorithm

First-Line: Topical Therapy + Phototherapy

Topical corticosteroids are the most rapid and efficient treatment for guttate psoriasis:

• Apply moderately potent topical corticosteroids (grade III) as primary therapy 1, 3
• Limit to no more than 100g per month 1
• Require regular clinical review with no unsupervised repeat prescriptions 4
• Incorporate periods each year when alternative treatments are employed 4

Alternative topical agents for patients who fail corticosteroids or prefer other options:

• Coal tar: Start with 0.5-1.0% crude coal tar in petroleum jelly, increasing concentration every few days to maximum 10% as tolerated 4, 1

  • Use lower concentrations than for chronic plaque psoriasis, as erupting guttate psoriasis is less tolerant of topical treatment 4
  • Crude tar extracts are messier but more effective than refined products 4

• Dithranol (anthralin): Use cautiously in short contact mode (15-45 minutes daily) 4, 1

  • Start at 0.1-0.25% concentration and increase in doubling concentrations as tolerated 4
  • Warn patients about irritancy and staining of skin and clothes 4
  • Exercise great care on sensitive sites (face, flexures, genitalia) 4

• Calcipotriol (vitamin D analogues): Can be used alone or combined with corticosteroids for enhanced efficacy 5, 3

Phototherapy is especially helpful and has the most robust evidence:

• Narrowband UVB is the most effective phototherapy modality 2, 5
• Administer 3 days per week initially, decreasing to 2 days per week upon improvement 1
• Treatment courses typically last 8-10 weeks 1
• More practical than topical therapy when treating widespread or numerous small lesions 3

Antibiotic Therapy

If active streptococcal infection is documented, treat with phenoxymethylpenicillin or erythromycin 4, 1

However, recognize that evidence suggests minimal connection between underlying infection resolution and GP lesion remission 5. Antibiotics should be considered supportive therapy rather than primary treatment 5.

For recurrent guttate psoriasis following documented recurrent tonsillitis, refer to otolaryngology for consideration of tonsillectomy 4, 1

Second-Line: Systemic Therapy

For moderate-to-severe cases that fail first-line therapy:

• Methotrexate or cyclosporine are recommended as second-line options 5, 3
• Traditional immunosuppressants should be reserved for patients who fail phototherapy and topical therapies 3

Third-Line: Biologics

For severe and refractory guttate psoriasis, biologics can be used as third-line treatment 5

• Biologics like ustekinumab are recommended for moderate-to-severe cases that fail conventional therapy 2

Critical Pitfalls to Avoid

• Never use systemic corticosteroids—they can cause disease flare during taper 1, 2
• Do not use commercial sunbeds (emitting UVA), as they are rarely effective and may cause significant side effects 2
• Recognize that guttate psoriasis is self-limiting in most cases, resolving within 3-4 months without scarring 4, 1, 3
• However, 40-50% of cases may persist and progress to chronic plaque psoriasis, justifying active treatment 3
• Some patients who fail one topical agent will respond to another—try alternative topical agents before escalating to systemic therapy 4

Monitoring and Follow-Up

• Regular clinical review is essential when using topical corticosteroids 4
• Use body mapping or area and severity index (PASI) to objectively track improvement 4
• Reassess treatment response every 2-4 weeks and adjust therapy accordingly 4