19 February 2026
: Case report 
Guttate Psoriasis Triggered by Streptococcal Pharyngitis in Older Patients: A Case Report
Unusual clinical course, Challenging differential diagnosis
Dhanya E. Thomas ABE 1*, Amritha Gunasekharan AE 2, Rathna K. Yallapragada AB 3DOI: 10.12659/AJCR.950215
Am J Case Rep 2026; 27:e950215
Table 1 Timeline of clinical course seen in the patient (refer to the Case Report section).
| Timeline | Date | Events/findings | Treatment/response |
|---|---|---|---|
| Initial pharyngitis | December 18, 2024 | PCR +ve for Streptococcal pharyngitis | Azithromycin 500 mg: 250 mg for 4 days* |
| Gastroenteritis | December 22, 2024 | Norovirus infection | Supportive treatment and an abrupt stop to her antibiotics |
| Rash onset | December 28, 2024 | Red scaly macules on her abdomen | Misdiagnosed with Tinea vesicolor |
| Dermatology referral | January 3, 2025 | Rash progression with elevated ESR/CRP | Clinical suspicion with the decision to do a biopsy |
| Diagnosis | January 20, 2025 | Biopsy confirmed guttate psoriasis | Treatment initiation with Clobestasol 0.05% BID |
| Improvement | March 2025 | Marked regression with pain resolution | Continue therapy |
| Follow up | July 29, 2025 | No recurrence | Stable condition |
| * Azithromycin dosing: 500 mg on day 1 followed by 250 mg daily for 4 days. ESR – erythrocyte sedimentation rate; CRP – C-reactive protein. Tinea versicolor – superficial fungal infection caused by Malassezia species. | |||