Skin injuries associated with biological therapy in inflammatory bowel disease: Beyond psoriasis

We report the case of a 43-year-old man with Crohn’s disease of the ileum and colon. He was treated initially with steroids and azathioprine and then with adalimumab (ADA). He remained stable until four years ago, when he developed complex perianal disease (PAD). As ADA failed to manage his PAD, he was started on vedolizumab (VDZ) (Fig. 1).

Figure 1.

Palmar–plantar involvement in the form of erythematous papules with a hyperkeratotic scaly collarette that may take on a psoriasiform appearance. Larger lesion in the form of localised hyperkeratosis (black arrow).

The treatment with VDZ brought both his bowel signs and symptoms and his PAD under control. After three years of this treatment, the patient developed a pruriginous palmar–plantar hyperkeratotic maculopapular rash. In his family history, he had a brother with psoriasis. Dermatology diagnosed him by serology with secondary syphilis; he responded well to antibiotic treatment.

Biological drugs are a commonly used treatment tool in inflammatory bowel disease. Their adverse effects include the development of psoriasiform lesions, classically reported with TNF inhibitors, though also with other drugs such as VDZ.^1,2 In many cases, the drug has to be discontinued; therefore, a good differential diagnosis of these lesions with infectious diseases such as syphilis is essential.^3,4 The characteristic sign of secondary syphilis is palmar–plantar involvement manifesting as erythematous papules with a scaly collarette that may take on a psoriasiform appearance. Nail involvement is rare. Treatment does not require discontinuation of the biological drug, but rather antibiotic therapy with penicillin.^4,5

Funding

The authors declare that they received no funding to conduct this study.