Hello,
More information is needed for a better answer. I'll give you my best with the presented information.
Your husband has mild
neutropenia. His
neutrophil count is not so low to justify the infections you mentioned unless his white blood cells are not functioning as supposed.
Important information would be whether he has enlarged lymph nodes or not, body weight changes, the exact site of tingling and numbness, if he still has symptoms or not, the presence of fever etc (I'll mention more in my answer)
Drugs is one of the most common causes of white blood cell count disorders.
Infections could also cause such disorders lasting for several weeks or even months - mostly viral but also
tuberculosis and rickettsial infections.
Other possible causes which need evaluation are autoimmune conditions such as systemic
lupus erythematosus etc. There are diagnostic criteria for them (clinical and laboratory). The presence of
antibodies in the blood is a significant part of the investigation for these conditions.
His easy bruising problem should be better addressed with INR (international normalized ratio) and aPTT (activated partial
prothrombin time) tests. These tests cover the most common causes of
hemostasis problems.
As I already mentioned the provided information is not sufficient for a complete answer. For example, if your doctor has pointed out a likely cause (a drug, an infection) then his "wait and watch" approach seems rational to me.
Feel free to ask again, should you need further clarification, but please provide some of the clues I mentioned.
I hope he gets better!
Kind Regards!