What sort of blood test can indicate abnormalities if there is inflammation in the penile region? can glandular fever have any connection?

Labs are secondary: Visible lesions here are diagnosed primarily on the physical exam. If the lesion could be syphilis, you'll want labs. If the lesion could be chlamydia / gonorrhea, microbe studies. If it's a visible lesion, consider biopsy. Big lymph nodes? History and physical exam.

General & specific: Some lab test abnormalities indicate Inflammation in general (anywhere in the body) such as increased white blood cell count, erythrocyte sed rate etc while other lab tests can be specifc for the involved organ like biopsies