Definition. A spreading vesicular inflammation of the skin, usually following an injury upon the upper extremities.
Symptoms. This disease was first described by Crocker in 1888, following the observation of three cases. An injury which often is trivial, precedes and marks the starting point of the eruption, which consists of vesicles and bullae. These rupture and leave the epidermis completely denuded, exposing a red, raw and oozing surface. It is from the borders of this area that the vesicular extension so typical of the disease takes place. This has been described as a serous undermining of the epidermis, and consists in the formation of new vesicles and blebs in the area beyond the periphery of the old lesion, and in the detachment of the epidermis as a result of the exudation. The condition is often limited to the hand, but may extend to the arm, back, or even to the other arm.
Acrodermatitis perstans, a condition similar in location, origin, lesions and clinical history to dermatitis repens has been described by Hallopeau, Andry, and others. Its characteristics are the frequent appearance of secondary eruptions, chiefly pustular, on parts of the body distinct from the seat of the original infection, its frequent reappearance in the same place, its place persistence and possible fatal termination.
Etiology and Pathology. Most cases originate from some local traumatism, often trivial. Among the reported causal incidents, may be mentioned superficial wounds of burns of the hand, an abrasion of the knuckles, a splinter run under the nail, a scratch on a finger from a bone, the tearing away of a finger nail and, in a case of may own, repeated prickes on the index finger from a needle. The process seems to be due to a peripheral neuritis, set up by an injury. Secondary parasitic infection is generally admitted to be responsible for the prolonged course of these allied disease, but Hallopeau regards both as purely microbic. The staphylococcus albus has frequently been found in the lesions.
Diagnosis. These conditions should be readily diagnosed from eczema by their elevated, abrupt, and advancing border, producing the appearance of a superficial ulcer. Syhilis, lupus vulgaris and epithelioma might possibly call for microscopic investigation.
Prognosis and Treatment. Complete recovery may be expected in all cases of dermatitis repens, and in all but the more severe cases of acrodermatitis perstans. Treatment demands that the undermined weak solution of electrozone or hydrogen peroxid before applying such antiparasitics as a 10 per cent. ammoniated mercury ointment, 5 to 10 per cent. solution of potassium permanganate, saturated solution of sodium hyposulphite or pyoktanin-blue. The X-rays, high-frequency currents, and short superficial applications cases. See indications for Carbolic acid, Hepar sulph., Lachesis, Mercurius viv., and Ranunc. bulb.