<prompt> Commonest cause of acute folliculitis hair follicle infection isStaphylococcus aureusBeta hemolytic streptococcusPropionibacterium acnesStreptococcus viridans  <response>: Acute folliculitis are of two types: superficial and deep. The most common causative organism is Staphylococcus aureus. Superficial folliculitis is also caused by Pseudomonas aeruginosa.Reference : page 41 IADVLs Concise Textbook of Dermatology 