Biologic Therapy Infection Risks: What You Need to Know

When you’re dealing with rheumatoid arthritis, psoriasis, or Crohn’s disease, biologic therapy, a targeted treatment that blocks specific parts of the immune system to reduce inflammation. Also known as biologics, it can change your life—but it also comes with a hidden cost: increased risk of serious infections. These drugs don’t weaken your whole immune system like chemo does. Instead, they silence specific signals—like TNF-alpha or IL-17—that drive inflammation. But by doing that, they also make it harder for your body to fight off bacteria, viruses, and fungi.

The biggest concern? TNF inhibitors, a common class of biologics including adalimumab and infliximab. Also known as anti-TNF drugs, they’re linked to higher rates of tuberculosis, fungal infections like histoplasmosis, and even rare neurological infections. If you’ve lived in or traveled to areas where these fungi are common—like the Ohio or Mississippi River valleys—your doctor should test you before starting. Even a minor cut or a cold can turn serious if your immune system is tuned down. And it’s not just about catching something new. Latent infections like hepatitis B or TB can wake up after years of being quiet.

It’s not all bad news. Most people on biologics never get a serious infection. But you need to be smart. Get your flu shot every year—just not the live version. Stay up to date on pneumonia and shingles vaccines. Avoid close contact with sick people, especially during cold and flu season. Wash your hands. Check for redness, swelling, or fever after minor injuries. If you develop a fever, chills, or unexplained fatigue, don’t wait. Call your doctor. These drugs work best when you’re not fighting an infection on top of them.

The posts below dig into real-world cases: how biologic therapy connects to antibiotic resistance, why some patients get recurrent yeast infections, how to spot early signs of infection before it’s too late, and what alternatives exist if the risks outweigh the benefits. You’ll find practical advice from people who’ve been there—no fluff, no jargon, just what matters for your health.