Guttate psoriasis is classically triggered by which infection?

• A. Emotional stress
• B. Trauma to skin
• C. Strep throat infection
• D. UV exposure

Answer: (C)

Guttate psoriasis is most classically precipitated by a streptococcal throat infection. After a strep pharyngitis, the immune response can provoke a widespread eruption of numerous small drop-like papules on the trunk and proximal limbs, typically appearing within a couple of weeks. This link is tied to a specific immune activation pattern involving Th1/Th17 pathways and cross-reactivity that drives rapid skin inflammation. While stress or skin trauma can worsen psoriasis in general, they are not the classic trigger for the guttate form, and UV exposure is usually a treatment modulator rather than a trigger. Hence, a recent streptococcal throat infection is the best answer.