A 5-year-old boy with food allergies complicated by anaphylactic reactions with dyspnoea and angioedema had been prescribed an autoinjector with epinephrine (0.15 mg) so that his parents could treat him at home if necessary. The patient accidentally injected himself in a finger, which likely makes him the youngest patient to receive an epinephrine auto-injection reported to date. Treatment consisted of phentolamine (0.15 mg in 0.5 ml normal saline) injected subcutaneously at the site of accidental injection; the dose and volume were not adapted according to the age and body weight of the patient as only a local effect was intended. Finger circulation was restored within 20 minutes. Headache, nausea and vomiting were observed after 30 minutes and were most likely a systemic side effect of phentolamine. No other complications occurred. The patient recovered fully and was discharged the following morning. Intramuscular epinephrine autoinjection is standard therapy for severe anaphylactic reactions. The epinephrine autoinjector was introduced in 1980. As allergy and anaphylaxis become more common, increasing numbers of autoinjectors are prescribed, and it is likely that the number of accidental digital autoinjections will also increase. These digits are then at risk of ischaemic necrosis. There is no consensus on therapeutic strategies in such cases. Phentolamine administration appears to be an effective intervention. However, several recent studies have shown that epinephrine may be used safely in hand surgery, which suggests that accidental digital epinephrine autoinjection may not always require immediate treatment.