A 61-year-old otherwise well male patient presented with painful, red, increasingly swollen gingivae and occasional gingival bleeding with tooth cleaning that has been worsening over the past 6-7 months. There has been some superficial ulceration of the lower left gingivae. There is no identifiable initiating factor. The clinical symptoms and signs have persisted despite assessment by a specialist in periodontology, debridement of calculus and the patient maintaining a fair level of oral hygiene. A recent full blood cell count undertaken by his general medical practitioner revealed no abnormalities. The patient is single, employed as a concierge, does not smoke tobacco or other preparations, rarely drinks alcohol, and has a history of contact dermatitis for which he occasionally takes fexofenadine.

figure 1

Can you identify or diagnose what is shown in the image? Send your answers to k.quinlan@nature.com by 9 February 2023. The answer will be revealed in an upcoming issue.

If you would like to send a clinical puzzle, view the details here: https://www.nature.com/articles/s41415-022-5392-2.