11/14. Ultrastructure of the Arthus Phenomenon in muscle. Specific blood-tissue barrier alterations were observed in a 2-year-old boy with a myopathic lesion in his muscle. Close by, degenerative changes were present in muscle fibers, three types of vascular abnormalities, i.e. increased vascular permeability, neutrophil aggregation, and damage of endothelium with thrombi formation, suggest that a process of vasculitis took place in the muscle of this patient. On the basis of current information it is not entirely clear whether this Arthus-like reaction observed in the primarily affected muscle represents a widespread vascular bed defect or whether it is the consequence of an additional secondary symptom possibly dependent upon muscle necrosis. ( info) |
12/14. An unusual skin reaction following local anesthetic injection. review of the literature and report of four cases. Four cases of an unusual skin eruption related to mandibular block injection are presented. The authors suggest an immunologic basis for the reaction, probably to the methylparaben preseravtive, and discuss a possible pathogenic mechanism. The medical-dental literature concerning untoward reactions to lidocaine is reviewed; particular attention is given alleged allergic reactions. ( info) |
| purpura fulminans presents as a catastrophic illness with gangrene of the distal extremities and necrosis of skin. The clinical picture consists of septicemia, shock, and disseminated intravascular coagulation. The Shwartzman and Arthus reactions are thought to be responsible for the pathogenesis of purpura fulminans. The exact mechanisms of these reactions are not completely understood. Immediate resuscitation is the treatment for shock and sepsis. heparin is recommended to reverse the disseminated intravascular coagulation component of this disease. Surviving patients require treatment of skin necrosis and digital and extremity gangrene. The former are managed in a fashion similar to the management of burns. amputation should be delayed until maximal collateral circulation has developed. A series of 10 patients is presented and 58 cases from the literature are analyzed. ( info) |
14/14. Wessely-type immune ring following phototherapeutic keratectomy. Immune rings following photorefractive keratectomy (PRK) have been reported but have not been described in detail. This case report describes an immune ring after phototherapeutic keratectomy (PTK) in a patient with long-standing superficial corneal scars. A dense white ring formed in the peripheral cornea on the fourth day following surgery. The patient was treated with antibiotics until negative cultures were reported 48 hours later. A biopsy was taken and examined by light microscopy using hematoxylin-eosin and Mason's trichrome staining. The stroma showed focal keratocyte depopulation with nuclear fragments, occasional polymorphonuclear leucocytes, and an active fibroblastic reaction. No lymphocytes or plasma cells were seen. Clinically, the immune ring faded slowly and was still apparent 9 months after the PTK. Studies of similar cases are required to clarify the mechanisms responsible for this phenomenon. ( info) |