How do you approach PJP prophylaxis in patients with rheumatic disease on corticosteroids?   

The guidelines for the need for PJP prophylaxis are generally based on the dose of corticosteroids alone (>20 mg prednisolone or equivalent qd for >4 weeks) or steroids in combination with other agents such as azathioprine, cyclophosphamide, or methotrexate. The presence of underlying ILD...

Here is a graphic I made covering PJP Prophylaxis with Dr. @Cassie Calabrese if anyone is interested!   As noted, one can check absolute lymphocyte count (ALC) or CD4 count as factors to further risk stratify as well.

I tend to look at the total lymphocyte count - if it is <400/mm³ or embarking on an immunosuppression regimen very likely to effect that (which the guidelines alluded to by Dr. @Smulian are somewhat predictive of) I will initiate PJP prophylaxis. See: Tang et al., PMID 33912176

@Walter W. Chatham: Thanks so much for the Tang article. This is my first time seeing it. Question for you: Why do you choose an absolute lymphocyte count (ALC) less than 400? In Figure 3 of the article, only 2-3 of the patients appear to have an ALC of 200 or higher. If so, I just wonder if a level...