Photo‐induced graft‐versus‐host disease

Overlap chronic graft‐versus‐host disease (GVHD) associates both features of acute and chronic GVHD. Trigger factors for chronic GVHD are unclear. We describe two patients who received allogenic haematopoietic stem‐cell transplantation, and who later developed overlap chronic GVHD after sun exposure. Available data from in vivo investigations suggest ultraviolet B radiation (UVB) has a beneficial effect on acute and chronic GVHD. The role of sun irradiation as a trigger for isomorphic cutaneous GVHD has been rarely reported in the literature. Herein, we demonstrate for the first time, using repetitive broadband phototesting, that UVB triggers chronic GVHD.     

Docetaxel‐induced photo‐recall phenomenon

Photo‐recall phenomenon is a phototoxic eruption occurring on areas of previous ultraviolet‐induced solar erythema following a systemic administration of a drug. It has been mostly described with methotrexate but remains rare with other antineoplastic drugs. We describe a case of docetaxel‐induced photo‐recall skin rash in a woman treated for a non‐small‐cell lung cancer. Although the patient has refused to receive a second infusion, chemotherapy can be carried on with photoprotection and the use of topical and/or systemic corticosteroids. In contrast, radiation recall is a well‐known reaction by oncologists, most of them may not be aware of a similar phenomenon called photo‐recall phenomenon. Recognizing this entity may avoid misdiagnosing a drug allergy and should avoid inappropriate decisions of drug discontinuation.     

Doxycycline‐induced hypoglycaemia

Tetracyclines, including doxycycline, are widely used drugs that form an integral part of daily prescribing, and serious adverse reactions (SARs) are rarely reported. The frequency of hypoglycaemia complicating tetracycline treatment remains unknown, and is not a recognized complication. We describe an 80‐year‐old man with a history of insulin‐dependent diabetes who was recruited into a large research study, and subsequently experienced the unexpected SAR of hypoglycaemia following treatment with doxycycline.     

Warfarin‐induced erythroderma

Erythroderma is a potentially serious and life‐threatening skin disease with a number of possible aetiologies. Drug reactions are well‐documented causes, with carbamazepine, penicillin and allopurinol being the most commonly implicated. This case describes a unique presentation of warfarin‐induced erythroderma in a 78‐year‐old female patient.