E M E R G E N C Y   M E D I C I N E

HISTORY:

A 35 year old New York City sanitation worker presented with excruciating left sided neck and face pain. He had loaded several bags of trash into the compactor of his truck 3 hours earlier and an unknown liquid had gushed out onto his face and neck. He washed the substance off within minutes, omitting his neck, but felt increasingly sharp pain for the remaining 2 1/2 hours of his shift.


PHYSICAL:

Examination revealed multiple blotchy areas of gray- green discoloration over the left side ot his neck corresponding to the area of greatest pain. There was less pain on the left side of his face, which was speckled with fine gray green spots. The total area affected was about 1%.


ANCILLARY TESTS:

SMA-7 = normal
CBC = normal
EKG = normal



HOSPITAL COURSE:

The pain was disproportionate to the skin lesions and was not relieved by saline irrigation. The neck pain was relieved immediately on local infiltration of the lesion margins and beyond with 10% calcium gluconate. The facial pain was relieved within 20 minutes of applying calcium gluconate gel to the lesions.

DIAGNOSIS AND DISCUSSION

The history and findings on physical examination were consistent with a chemical burn. Pain from a chemical burn that is out of proportion to the actual physical injury is typical of exposure to hydrofluoric acid (HF), a substance available in various concentrations, and used in many industrial settings. In New York City, HF exposure is typically seen on the hands of workers who have used the chemical to clean brick or remove graffiti from walls.
Skin exposed to HF may at first appear normal and then develop poorly vascularized blisters. HF's toxicity results primarily from exposure to highly active fluoride ions. The substance slowly dissociates, causing liquefac tion necrosis, decalcification of bone, and precipitation of calcium fluoride and magnesium fluoride. An HF burn over 2.5% of the skin surface can result in life threaten ing systemic toxicity from hypocalcemia and hypomag nesemia. Because symptoms are often delayed, adequate decontamination may not have been carried out, so ini tial treatment centers on limiting the exposure and irri gating the exposed area.
Calcium is useful in precipitating reactive fluoride and relieving pain. This can take the form of calcium glu conate gel applied to the involved area and calcium glu conate injected intradermally if the area can be infiltrated. Intra arterial calcium gluconate should be used when these measures yield poor pain relief or there is poor ac cess to the exposed area (eg, under the nail bed). Intra venous calcium is employed in cases of systemic toxic ity. Magnesium therapy has also been advocated, but the evidence of its benefit is inconclusive. If HF has been in haled, the patient should receive nebulized calcium glu conate. Opioids are used in conjunction with the above measures to achieve satisfactory pain control.

Submitted by Carl K. Hsu, MD, Chief Resident,
Mount Sinai School of Medicine Integrated
Residency in Emergency Medicine at Beth Israel
Medical Center and Elmhurst Medical Center;
Christine Stork, PharmD, Fellow, Toxicology and
Emergency Medicine, New York University and
Bellevue Hospital Center, New York City Poison
Control, Department of Health; and Robert
Dreilinger, MD, Director, Emergency Department,
Jackson Heights Hospital, New York