High-pressure water injection injury

Patients that present with high-pressure injection injuries most often have hand or digital involvement. Overall, highpressure injection injuries to the hand are uncommon and tend to be occupation related. The usual cause is industrial equipment, with machinery such as grease guns, spray guns and diesel engine injectors accounting for most of these injuries. Materials injected include the following reported substances: paint, paint thinner, grease, oil, hydraulic fluid, plastic, wax, water and semifluid cement. The extent of damage from high-pressure injection injuries depends on a number of physical, chemical and biological factors, including the type, amount and velocity of injected material and the anatomical location of the injury. For any injury that results in a significant depth of penetration, the most important determinant of the extent of injury is the chemical composition of the injected material. This determines the likely tissue inflammatory response and the resulting fibrosis that develops during healing. Paint and paint thinner produce a large, early inflammatory response and result in a high percentage of amputations. In contrast, grease injuries cause a small inflammatory response and have a lower amputation rate but are associated with oleogranuloma formation, fistulas, scarring and loss of digit function. The amount of material injected into the confined space of the digits or palm determines the degree of mechanical distention and the potential for vascular compromise. The velocity of the injected material and the site of tissue penetration determine anatomical dispersion, which for upper extremity injuries may include the digit, hand and forearm [1]. The patient who seeks treatment early after injury may have minimal symptoms with either an innocuous entrance wound or no visible break in the skin. Fusiform swelling resulting from mechanical distention of the tissue by the injectant will usually be apparent. Several hours later, the involved digit or palm may become extremely painful, swollen and pale because of vascular compromise and tissue necrosis [1]. The incidence of high-pressure water injection injury to the mouth or oral cavity appears to be quite rare. A literature search of MEDLINE yielded no reports of highpressure injuries to this region. The only literature detailing an oral water injury was described by Duplechain et al. in 1993 [2]. They reported on a 5-year-old girl who suffered an injury from a much lower pressure bathtub water spout. Here we describe a recent oral injury from a high power pressure washer.