Zithromax Stevens-Johnson Syndrome (SJS) Reaction Outlined in Case Study

Kidney failure or chronic kidney disease may increase risk of SJS from Zithromax and other antibiotics from a popular class known as macrolides.

Doctors report that a 52-year-old woman given the antibiotic azithromycin, commonly known by the names Zithromax or Zpack, experienced a dangerous skin reaction that took months to heal.

In a case study published in the medical journal Cureus on August 4, University of Maryland researchers say the woman is at least the twelfth known case of Stevens-Johnson Syndrome linked to azithromycin-based antibiotics, and about two dozen have been linked to the entire class of infection-fighting medications, known as macrolides.

Macrolides are a popular class of antibiotics frequently prescribed to treat common bacterial infections like respiratory infections, skin and soft tissue infections and sexually transmitted diseases. They include Zithromax, as well as Biaxin, Dificid and Erythromycin.

Stevens-Johnson syndrome is a serious and potentially life-threatening skin reaction that has been linked to side effects of several different classes of medications, which produces painful blisters and rashes when burns develop from the inside out, causing the skin separating from the body.

When the skin lesions affect more than 30% of the body, SJS is then referred to as toxic epidermal necrolysis (TEN), which typically requires treatment in a hospital intensive care unit (ICU) or burn unit, often leading to disfiguring injuries, blindness or death. Almost nine out of 10 cases of SJS are caused by a medication reaction, and more than 200 drugs are known to potentially trigger the dangerous skin condition.

Dr. Mihir K. Patel, an assistant professor, and Jessica R. Lee, both from the department of internal medicine at the University of Maryland School of Medicine, presented a case involving a 52-year-old woman who took azithromycin, as prescribed, to treat a conjunctivitis infection. However, as a result, she began developing lesions in her mouth, which spread to her lips, as well as ulcers on her back and arms.

After being treated for several other possible causes without success, her primary care physician recommended she go to the emergency room, where doctors then recognized the pattern of an SJS reaction.

Based on the Alden scoring system, which is a tool used to assess the likelihood of a drug causing SJS, azithromycin received a score of nine, strongly suggesting it was the medication responsible.

Two factors may have complicated identification of SJS, the doctors noted, indicating that the woman had a COVID-19 infection and was suffering from end-stage renal disease, also known as kidney failure. First, doctors had to determine whether the patient was having a reaction to the coronavirus, which took time. Then researchers noted that while the liver does the heavy lifting of filtering out Zithromax, the renal system also plays a role, and her kidneys’ reduced functionality may have led to less azithromycin being filtered out of her blood, increasing the risk of a reaction.

After the cause of her sores and ulcers were identified, the patient was given corticosteroids for five days, which led to slight improvement. She was discharged with a prednisone prescription.

“Following her discharge from the hospital, the patient continued to experience complications. Her conjunctivitis took approximately one month to resolve, during which she reported a sensation akin to her eyelashes being forcibly removed.”

-Dr. Mihir K. Patel, Azithromycin-Induced Stevens-Johnson Syndrome in a Patient With SARS-CoV-2 and End-Stage Renal Disease

The patient’s oral ulcers began to dissipate within two weeks, but it took a month before she was able to begin to eat normally, and nine months later she still had scars on her arms and back, although they have continued to progressively heal over time, the researchers reported.

The team urged doctors to be aware of the potential risks of azithromycin, which is usually considered safe, and called for more research to understand the relationship between the antibiotic and immune system activation in patients with chronic kidney disease and end-stage renal disease.