Hard-to-treat psoriasis in a child developing neutralizing anti-drug antibodies against adalimumab during Streptococcus pyogenes throat infection: a case report

We report a case of a child with severe psoriasis vulgaris that developed neutralizing anti-drug antibodies against the biologic agent adalimumab 3 months after the first administration of the drug during Streptococcus pyogenes infection of the throat. After replacement of biologic agent, she was unsuccessfully treated with etanercept. Treatment with ustekinumab was the last option and initially it also appeared ineffective, but as we shortened the interval and doubled the dosage our patient's skin condition finally improved.