Answer 1 Exposure
Infection does not necessarily follow exposure. Only a small percentage of people exposed develop infection.
Answer 3 INH Chemoprophylaxis
The indications for INH chemoprophylaxis are:
Two considerations are:
If you look at all new patients with active tuberculosis, you will see that 95% of the cases are coming from patients who had positive skin tests previously. The risk for active tuberculosis in people with negative skin tests is so small, it is not worth the effort. That excludes about 200 million people in the United States. There are approximately 10 million people with positive skin tests. Let us next consider the statistical probability of developing tuberculosis:
The risk of developing INH liver toxicity is greatest in:
Answer 4 Exposure
Yes. Retest again in three months. If still negative, stop the INH.
Answer 5 Exposure
Being a household contact, he will be a candidate to receive prophylaxis, irrespective of skin test results.
Our concern is, what is the risk of developing INH hepatitis? With increasing age, the risk of developing hepatitis with INH increases. His skin test results may suggest that he is not infected or that there has not been enough time for him to develop an immunological reaction.
Multiple myeloma is a B cell disease. As such, patients have problems with immunoglobulins. Only patients with T cell problems have a higher risk of developing tuberculosis.
These are the issues we have to consider before deciding on chemoprophylaxis. We have two options:
I follow the second option.
Answer 6 Exposure
She has a positive skin test and is a home contact. However, she had been positive five years ago. Once you've had an infection, you're protected from exogenous infection. If she gets the disease, it will be from reactivation or endogenous focus. She is not a candidate for prophylaxis.