Gram-negative folliculitis is a type of bacterial infection that can be mistaken for a rash or acne. There are a number of different types of gram-negative bacteria, including Pseudomonas aeruginosa, Klebsiella, Serratia marcescens, Escherichia coli, and Poroteus.
One of the causes of gram-negative folliculitis is long-term treatment of acne with antibiotics. Hot tubs and spas can also cause a type of gram-negative folliculitis known as "spa pool folliculitis".
Gram-negative folliculitis tends to be found on the face, specifically around the lips, nose, cheeks and chin.
Gram-negative folliculitis is more common in people who have acne or rosacea and have been treated long-term with antibiotics.