Thanks for your question posted to HCM website, As can be seen, your chief complaint is about a bump in the groin area of a man while it became bigger within several months. To address any kind of abnormality visualized in groin area, there are many differential diagnosis including Infections such as herpes, Syphilis, Chancroid, Tuberculosis, Lymph node and orchids, Skin and sub-skin abscesses, Epididymitis, Orchitis, Cellulitis, Folliculitis, Neoplastic Disorders such as Melanoma or Hodgkin s disease, Adenocarcinoma, Prostate disorders, Foreign Body and anatomical disorders such as Inguinal hernia, Inguinal adenopathy, etc. To address only STD groups, the patient has to be tested for differential diagnosis of such microbes including Bacterial (Chancroid by Haemophilus ducreyi, Chlamydia trachomatis, Neisseria gonorrhoeae, Klebsiella granulomatis, Mycoplasma, Syphilis by Treponema pallidum), Fungal infections, also Viral factors such as Herpes, Hepatitis B virus and HIV or Human Immunodeficiency Virus.Parasites such as Scabies may demonstrate similar signs and symptoms. Regarding instructions posted by you and my experience, my recommendations are: 1. You have this right to be anxious about the cause of that disorder in your boyfriend and I suggest you seriously follow up his illness to reach an exact diagnosis. 2. After visiting his doctor, he would be ordered to perform several tests for the purpose of differential diagnosis written above. 3. According to the time duration, it is hardly acceptable the lesion is only a simple skin folliculitis and it means the patient demands more advanced follow-up and tests. Hope you find my suggestions useful, Regards