Novel use of Autoinflammatory Diseases Activity Index (AIDAI) captures skin and extracutaneous features to help manage pediatric DITRA: A case report and a proposal for a modified disease activity index in autoinflammatory keratinization disorders

Generalized pustular psoriasis (GPP) is a severe form of psoriasis, which is rare in pediatric and adult patients. It is characterized by sterile pustular lesions that appear on erythematous skin, associated with systemic features. A recent identification of mutations in the IL36RN gene in some GPP patients has led to a diagnosis of new autoinflammatory disease, interleukin-36-receptor antagonist deficiency (DITRA). DITRA represents an emerging group of autoinflammatory diseases with hyperkeratotic skin involvement, called autoinflammatory keratinization diseases (AIKD). DITRA diagnosis and management are challenging as neither DITRA-specific clinical assessment tools nor treatment trials exist. Autoinflammatory Diseases Activity Index (AIDAI) is a validated tool originally developed to evaluate disease activity and treatment response in other inherited autoinflammatory diseases with systemic and skin involvement. We report the first use of AIDAI in a pediatric DITRA patient with the following goals: (a) to describe the contribution of AIDAI to our patient's management; (b) to identify potential limitations of AIDAI in DITRA; (c) to review literature for current psoriasis assessment tools; and (d) to propose a preliminary DITRA/AIKD disease activity index (DITRA/AIDAI) to be validated in future studies.