Hydrofluoric acid (HF) is a colorless, corrosive liquid available in both commercial (> 20%) and household (< 20%, typically 6%-12%) formulations. Commercially, HF is used in glass etching, electroplating, and semiconductor manufacturing. Consumer products are typically marketed as rust removers and chrome cleaners. Although toxic via the dermal, ocular, pulmonary, and GI routes, most patients present after dermal exposure, typically to the hands and fingers. The severity of local injury depends on the HF concentration and the extent of exposure.
Symptoms and tissue effects may be appreciably delayed, especially with household formulations. In the setting of hand exposure, pain is typically described as a progressive, severe, unremitting, deep burning sensation. Early local erythema is variable. Especially with higher HF concentrations, a pale blanched appearance may develop. HF causes coagulative necrosis similar to other inorganic acids, but may also result in toxicity by the binding and precipitation of calcium ions. In addition to local effects, significant and potentially life-threatening systemic effects may occur including hypocalcemia, hyperkalemia, and hypomagnesemia. Concentrations greater than 50% may cause rapid decompensation with even small dermal exposures (1% total body surface area [TBSA]).
Management and Disposition
Treatment varies depending on the route of exposure but is directed toward decontamination, neutralization of the fluoride ion, and pain control. In the setting of ingestion or significant dermal exposure (> 5% TBSA of a household HF formulation), serum electrolytes, including calcium and magnesium, should be obtained. In addition to pain control, management options for hand burns include commercially available calcium gluconate gel, subcutaneous calcium gluconate infiltration, and regional intravenous and intra-arterial calcium gluconate infusion.
An expedient 2.5% calcium gluconate gel can be made by adding 3.5 g of calcium gluconate powder to 5 oz (150 mL) of water-based lubricant. Alternatively, 10 crushed 1-g calcium carbonate antacid tablets may be added to 20 mL of water-based lubricant. The resultant gel may be placed in a rubber glove and placed on the patient’s hand for topical treatment (see Fig. 17.76).
With significant dermal exposure or ingestion, prolonged cardiac and serum electrolyte monitoring may be required; sudden delayed cardiac arrest has occurred.
Replacement of calcium and magnesium may require substantially larger doses than typically required.
Hydrofluoric Acid Burns. These hydrofluoric acid burns are due to application of a rust remover agent. The patient presented hours later after initial use with severe deep pain in the thumb and index finger. (Photo contributor: Karen Rogers, MD.)
Hydrofluoric Acid Burn. This patient suffered severely painful hydrofluoric acid burns to the hands. The exposure resulted from the use of commercial chrome cleaner. (Photo contributor: Kevin J. Knoop, MD, MS.)