LAUSR

Dear Editor, Extensive neutrophilic activation and infiltration occur in a number of dermatological conditions, resulting in typical features of pyrexia, neutrophilia, and raised erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). These conditions are namely generalised pustular psoriasis, acute generalised exanthematous pustulosis (AGEP) and Sweet syndrome, and they are termed as neutrophilic dermatoses with systemic manifestations. Their presentation is similar to that in patients with severe bacterial infections, such as severe pneumonia, peritonitis, meningitis, pyelonephritis and sepsis. Early differentiation between neutrophilic dermatoses with systemic manifestations and severe bacterial infection is important due to the opposing treatment approaches. Whilst patients who have neutrophilic dermatoses with systemic manifestations require immunosuppressive therapy,1,2 patients with severe bacterial infections require antibiotic therapy, and the use of immunosuppressive therapy should be avoided. In the last decade, extensive research has been undertaken to study the diagnostic value of procalcitonin in bacterial infections.3-6 The primary objective of this study is to evaluate the predictive value of procalcitonin for the presence of severe bacterial infections in patients who have neutrophilic dermatoses with systemic manifestations. If the procalcitonin levels in these patients are not elevated, clinicians can better decide if they can be commenced promptly on immunosuppressant for their underlying skin condition. The secondary objective is to evaluate if procalcitonin levels differ between generalised pustular psoriasis and AGEP, as it is clinically and histologically difficult to distinguish these 2 conditions.