Cutaneous abscess Unusual bacterial skin infection Unusual bacterial skin abscess Unusual skin abscess Increased susceptibility to bacterial skin abscesses, as manifested by recurrent, multifocal, or unusually severe collections of pus within the dermis or deeper skin layers. While common causative organisms include Staphylococcus aureus and Streptococcus species, this term also encompasses abscesses caused by opportunistic or atypical bacteria, or those that are refractory to standard antibiotic therapy.