This invention provides methods of diagnosing and treating any C. pneumoniae infection of the skin including C. pneumoniae-associated diseases such as cutaneous T-cell lymphoma (CTCL), mycosis fungoides, Sezary syndrome, lymphomatoid papillosis, Ki-1 lymphoma, exfoliative exematous rash, and digitate parapsoriasis. This invention provides kits that are useful in the methods of the invention as well as for identifying new anti-chlamydial agents in treating skin infections. This invention includes a pharmaceutical vaccine composition comprising an antigen, including a full length antigenic determinant, such as any SAF positive determinant or portion thereof, which produces a detectable immune, humoral and/or cellular response to C. pneumoniae. The invention also includes a method of treating an active CTCL in a living being comprising delivering a therapeutically effective amount of a vaccine, wherein the vaccine comprises an agent, such as an inactivated C. pneumoniae material that produces a detectable immune, humoral and/or cellular response.