Limitations in the Use of the Dermo-Jet

To the Editor.— The Dermo-Jet is a convenient instrument for rapid injection of medication into the skin. It operates by producing a high-velocity microjet which penetrates the skin without a needle and without direct skin contact. The instrument is of special use in the intralesional injection of corticosteroids in a variety of skin diseases. We recently treated a patient who had cutaneous lupus erythematosus with triamcinolone acetonide which was administered intralesionally via a Dermo-Jet. During the injection of atrophic lesions on the cheek, we observed that the medication penetrated the full thickness of the skin and subcutaneous tissue, and perforated the buccal mucosa (Figure). Perforated buccal mucosa. The depth of penetration of the Dermo-Jet is stated by the manufacturer to be 4 to 6 mm. The thickness of the cheek is normally about 5 mm, but is reduced in areas of atrophy. Thus, it is not suprising that perforation of