In this video blog, Brittany Schultz, MD, discusses highlights from her lecture, Immunofluorescence/Immunobullous Work-up Tips & Tricks, on July 25, 2024, during the inaugural Elevate-Derm Alliance Summer Conference at the Westin Copley Place in Boston, Massachusetts.

In this video

Dr. Schultz explains that bullous pemphigoid triggered by immunotherapy looks very similar to the bullous pemphigoid seen in patients who aren't on immunotherapy, but it tends to occur later than other cutaneous immunotherapy reactions and may even persist after the immunotherapy is discontinued — so it stays on the differential even for a patient who has already completed treatment. She then walks through rituximab, a monoclonal antibody that targets CD20 on B cells for destruction so those B cells can no longer make the antibodies that cause destruction in pemphigus. A large study of 90 patients (rituximab plus prednisone vs. prednisone alone) showed significantly higher remission rates and fewer adverse events, establishing it as first-line for pemphigus.

She reviews the practical details — infusions in an infusion center, dosed either weekly for four weeks or once every other week for two doses, with a course potentially repeated about six months later — and emphasizes the pre-treatment work-up. Before rituximab, she orders baseline CBC and CMP plus screening for hepatitis B, C, HIV, and tuberculosis, stressing the triple serology (surface antibody, surface antigen, and core antibody) needed to interpret hepatitis B status and avoid reactivation. For long-term prednisone, she urges clinicians to "take a step back" and consider bone health (baseline DEXA, calcium/vitamin D, and possibly a bisphosphonate through primary care), peptic ulcer disease risk, infection screening, vaccination, and PJP prophylaxis where appropriate.

  • Immunotherapy-induced bullous pemphigoid presents like typical BP but appears later than other immunotherapy rashes and can persist after the drug is stopped — keep it on the differential even post-treatment.
  • Rituximab is first-line for pemphigus vulgaris because it targets CD20 B cells so they can't make the antibodies driving disease; a 90-patient study showed higher remission and fewer adverse events versus prednisone alone.
  • Rituximab is given in an infusion center, either weekly for four weeks or every other week for two doses, with a course potentially repeated around six months later.
  • Before rituximab, get baseline CBC/CMP and screen for hepatitis B, C, HIV, and TB — hepatitis B requires the triple serology (surface antibody, surface antigen, and core antibody) to interpret immune status.
  • With long-term prednisone, address bone health (DEXA, calcium/vitamin D, bisphosphonate), peptic ulcer risk, infection screening, vaccination, and PJP prophylaxis.