Adalimumab is widely used as first-line therapy for patients with moderate-to-severe psoriasis who require biological therapy.1 Although it is a drug with a favorable safety profile, it is not exempt from adverse effects. The relationship between anti-TNF agents and an increased frequency of upper respiratory tract infections and the development of tuberculosis is well known. However, there are other less frequent infections that may also be associated with these drugs.2,3

Our aim is to report a rare infection associated with adalimumab use in a patient with psoriasis.4

A 66-year-old man with hypertension and hyperuricemia, but without any other relevant past medical history, was being followed at another center for severe psoriasis. He had previously received treatment with acitretin, which was discontinued because of secondary failure, and ustekinumab, which was interrupted because of acute urticaria associated with its use. He initiated treatment with adalimumab, which was temporarily interrupted because of a transfer to another medical center. Two months after reintroduction of adalimumab, he developed persistent fever and low back pain, initially misinterpreted as a urinary tract infection and treated with oral cefixime. However, the fever persisted, and the patient was admitted to the hospital for further evaluation. Conventional radiography and computed tomography (Fig. 1a and b) revealed narrowing of the intervertebral space at the L2/L3 level with erosions of the vertebral endplates. The study was expanded with magnetic resonance imaging (Fig. 1c), which demonstrated phlegmonous changes in the area. In addition, blood cultures identified a strain of Streptococcus agalactiae without antimicrobial resistance, supporting the diagnosis of infectious spondylodiscitis.

Fig. 1.

(a) Radiographic image showing collapse of the L2–L3 vertebral space. (b) Sagittal CT scan demonstrating the abovementioned collapse and erosion of the vertebral endplates of L2 and L3. (c) Sagittal MRI T2-weighted sequence showing phlegmonous changes at the level of the intervertebral disc and adjacent soft tissues.

In view of these findings, IV ceftriaxone plus teicoplanin were administered and, after 3 weeks, treatment was de-escalated to high-dose oral amoxicillin until completing 12 weeks of antibiotic therapy. In addition, adalimumab was cautiously discontinued and psoriasis treatment was subsequently switched to guselkumab, with good clinical progression of both the infectious and cutaneous processes. Both conditions remained in remission 6 months after hospitalization.

Although adalimumab is considered a relatively safe drug, it may occasionally be associated with serious complications, including infections.2 Spondylodiscitis is a rare infection involving the intervertebral disc and adjacent vertebrae, whose hallmark symptom is usually insidious inflammatory low back pain.4 In patients with psoriasis, this is a common symptom, present in up to 20% of patients with skin-limited disease at the time of diagnosis. Therefore, diagnosis of such a serious complication may be delayed, and clinicians should remain alert to warning signs such as fever, refractoriness to analgesics, or, in the most severe cases, constitutional symptoms.4

Regarding this group of patients who require biological therapy but are at risk of infectious complications or who have experienced chronic infectious processes, several alternatives are currently available. Both clinical trial data and real-world experience indicate that anti-IL-17 and anti-IL-23 agents have a solid safety profile and are recommended as first-line therapies for patients with hepatitis B, latent tuberculosis infection, or other infectious comorbidities.5

In conclusion, our case highlights that inflammatory low back pain during treatment with adalimumab should be evaluated cautiously, since it may represent an infectious process for which a therapeutic target switch may be indicated.