Finger Pain out of Proportion to Exam: A Case of Occult Hydrofluoric Acid Toxicity

Abstract

IntroductionHydrofluoric acid toxicity can have significant morbidity and even mortality associated with seemingly small exposures.The impact of significant electrolyte disturbances can lead to sudden cardiac collapse.Owing to a delayed time to symptom onset, low concentration exposures may present as a diagnostic dilemma.The patient's lack of association between exposure and symptoms may eliminate key historical information.Additionally the lack of physical exams findings associated with low concentration HFA exposure adds to the challenges of making the correct diagnosis.We present a case of a 21-year-old male who presented to the emergency department with finger pain out of proportion to physical exam findings and no clear exposure to HFA. This case illustrates the importance of considering HFA toxicity in all unknown chemical exposures. Case ReportA 21-year-old male presented to the emergency department 12 hours after using a cleaning agent that was supplied by his employer to shine metal trim.The patient reported using non-waterproof gloves and no direct contact with the cleaning agent.Approximately one hour after using the cleaning agent, the patient reported feeling a painful prickly sensation that progressively worsened.The patient reported "multiple" visits to the sink to perform standard hand washing.The patient attempted using 1 dose of an oral non-steroidal anti inflammatory drug and a topical antibiotic ointment to sooth his discomfort without relief. Over the course of the next 8 hours the pain became intolerable and the patient presented to the hospital.Upon arriving at the emergency department the patient's vital signs included a blood pressure 143/102, heart rate 104, respiratory rate 22 per minute, temperature of 36.5°C, and an oxygen saturation of 99% on room air.His physical exam was unremarkable except for his hands.The palmar surface of all 5 distal digits on the right hand and the palmar surface of the distal left thumb demonstrated mild erythema.The first 3 digits on the right also demonstrated some minimal whitening on the distal tips.There was no edema, blisters or ulcerations.Neurologically the patient was completely intact including 2-point discrimination over the affected area.The patient empirically received an appropriate weight-based dose of morphine and ondansetron and a 1-literintravenous bolus of 0.9% NaCl solution. Basic laboratory tests were performed that included a complete blood count, a comprehensive metabolic profile, and coagulation studies.Initial studies revealed a white blood cell count of 14.32 x10 9 /L, sodium 139 mEq/L, bicarbonate 17 mEq/L, chloride 107 mmol/L, potassium 3.5 mmol/L, ionized calcium 1.09 mmol/L (normal: 1.18-1.29 mmol/L), magnesium 1.7 mg/dl (normal: 1.8-2.4 mg/dl).X-rays of the hand demonstrated no bony abnormality or foreign body. A 12-lead EKG was performed which demonstrated a normal sinus rhythm, without peaked t-waves, and normal intervals including the corrected Q-T interval.Based on the suspicion for HFA exposure, in conjunction with a med...