This type of psoriasis is commonly seen in children and may follow a streptococcal sore throat -

guttate or eruptive psoriasis: More commonly seen in children and young adults with a shower of small papules and plaques all over the trunk and limbs. Lesions occur as an abrupt eruption following upper respiratory tract infection or tonsillitis ,especially due to beta henolytic streptococci tiny rain drop like erythematous papules, eruted abruptly bilaterally symmetrical in a centripetal fashion associated wit HLA Cw6 prognosis - good resolve in 3-4 months. treating streptococcal infection does not alter the progress of disease IADVL textbook of dermatology , page 1032