TY - JOUR T1 - Primary mammary actinomycosis challenged with penicillin allergy JF - BMJ Case Reports JO - BMJ Case Reports DO - 10.1136/bcr-2020-235883 VL - 14 IS - 7 SP - e235883 AU - Josephine B de Leoz AU - Devi Suravajjala AU - Hashmi Rafeek AU - Vani Selvan Y1 - 2021/07/01 UR - http://casereports.bmj.com/content/14/7/e235883.abstract N2 - Actinomycosis is a subacute-to-chronic bacterial infection caused by gram-positive, filamentous, non-acid-fast, facultative anaerobic bacteria. It is a normal commensal bacterium found in the oral cavity and the lower reproductive tract of women. We present a case of primary actinomycosis of the breast. A postmenopausal woman, complicated by penicillin allergy, presented with a left breast lump clinically simulating malignancy. The first line of treatment for actinomycosis is penicillin. Due to a penicillin allergy, the patient was initially treated with doxycycline. However, doxycycline was discontinued due to tremors, and was replaced by clindamycin. The patient had a good clinical response with resolution of the abscess. ER -