the dermal microcirculation, which are influenced by the autonomic sympathetic nervous system, s,9 Skin hyperthermia caused by a direct noxious injury or a local reflex caused by an inflammatory reaction occurring deeper in the extremity can be detected easily and imaged by thermography)'9 This localized thermographic abnormality is distinct from the pattern seen in patients with RSD, which consists of difl'use thermal alterations in the extremities in a glove and stocking pattern, s, 9 Relative coldness is the most common manifestation. However, for unknown reasons, an affected hand or foot may be hyperthermic) ,9 These changes have been related to sympathetic vasoconstriction and to compensatory and rebound vasodilation of skin capillaries, respectively. 6,~,9 The RSD was characterized by hypothermia in the majority of our patients, although hyperthermia was also seen. Both hypothermic and hyperthermic reactions are abnormal and may represent different stages of the disease, because there should be no significant temperature differential between normal extremities.6.8-/0 Thermography is a noninvasive technique, without known biologic hazards, that readily confirms the diagnosis of RSD by graphically documenting the subjective complaint of pain. It therefore facilitates appropriate therapy, preventing permanent disability. We have shown that results parallel therapeutic response and may be useful in evaluating and monitoring responses to various therapies. R E F E R E N C E S 1. Bernstein BH, Singsen BH, Kent JT, et al. Reflex neurovascular dystrophy in childhood. J PEDIATR 1978;93:211. 2. Fermaglich DR. Reflex sympathetic dystrophy in children. Pediatrics 1977;60:881. 3. Jaeobs JC. Pediatric rheumatology for the practitioner. New York: Springer-Verlag, 1982:165-7. 4. Kozin F, McCarty D J, Sims J~ et al. The reflex sympathetic dystrophy syndrome. I. Clinical and histologic studies: evidence for bilaterality, response to eorticosteroids and articular involvement. Am J Med 1976;60:321. 5. Kozin FF, Ryan LM, Carerra GF, et al. The reflex sympathetic dystrophy syndrome (RSDS). III. Scintigraphic studies: further evidence for the therapeutic efficacy of systemic corticosteroids, and proposed diagnostic criteria. Am J Med 1981;70:23. 6. Hendler N, Uematsu S, Long D. Thermographic validation of physical complaints in psychogenic pain patients. Psychosomatics 1982;23:283. 7. Laxer RM, Malleson RM, Morrison RT. Technetium 99m-methylene diphosphate bone scans in children with reflex neurovascular dystrophy. J PED~ATR 1985;106:437. 8. Pochaczevsky R, Wexler CE, Meyers PH, et al. Liquid crystal thermography of the spine and extremities: its value in the diagnosis of spinal root syndromes. J Neurosurg 1982; 56:386. 9. Pochaczevsky R. Thermography in skeletal and soft tissue trauma. In: Taveras JM, Ferrucei F, Norman A, eds. Radiology: diagnostic imaging and intervention, vol 5. Philadelphia: JB Lippincott, 1987:1-7. 10. Feldman F, Niekoloff EL. Normal thermographic standards for the cervical spine and upper extremities. Skeletal Radiol 1984;12:235.