Medical Memoranda MEDICALJOURNAL 157 direct pressure on the optic chiasma from a dilated third ventricle (Brain, 1962), the exact mechanism cannot be categorically stated. The exact mechanism of recovery also cannot be fully explained, though it is known that recovery of vision can follow prolonged blindness in children with hydrocephalus (Lorber, 1967). Shaffer and Hetherington (1969) suggested that the neuroglial framework is more susceptible than the neurones to an increase in surrounding pressure, and this, of course, can regenerate when the pressure is relieved.For the help given in the care of this case we are grateful to Miss U. J. Hull, public health nurse, and to Dr. Christian Belcourt, visiting (Hjort, Rapaport, and Jorgensen, 1964).We report the effects of hyperbaric oxygen in a child with purpura fulminans and suggest that it merits further trial in this serious condition.CASE REPORT A boy aged 14 months was admitted to hospital with purpura and bruises on his legs extending up to the knees and some purpura on his face and arms of 3 days' duration. During the week before admission he had had a mild non-specific upper respiratory tract infection. On examination he had extensive and symmetrical purpura and ecchymoses on both legs and a few purpuric spots on the face and arms. There was generalized lymphadenopathy, the spleen was palpable, the throat was infected and inflamed, and there was left otitis media.Investigations.-Haemoglobin 12 g./100 ml.; white cell count 12,400/mm.3 (polymorphs 25%, lymphocytes 71%, monocytes 3%, eosinophils 1%); platelets 304,000/mm.3 Sedimentation rate 27 mm. in 1 hour (Westergren). Blood culture, electrolytes, urea, cholesterol, immunoglobulins, prothrombin time, and kaolin/ cephalin time normal. Excessive fibrinolysis absent. Serum proteins 6-7 g./100 ml. (albumin 3-85 g., and globulin 2-85 g.). Urine and faeces examination negative.Despite treatment with cloxacillin (50 mg./kg./24 hours), fusidic acid (Fucidin) (20 mg./kg./24 hours), and prednisolone 5 mg. sixhourly (increased after 24 hours to 10 mg. six-hourly), his condition deteriorated greatly during the next 48 hours. Fresh ecchymoses appeared on his legs. Pedal pulses were almost impalpable, and all his toes had become tensely swollen and black, giving the appearance of cutaneous gangrene. He became oliguric, his face became puffy-the eyes being almost closed by oedema of the eyelids-and he developed macroscopic haematuria. Occult blood was present in the stools. In view of the early signs of gangrene it was decided to try the effect of hyperbaric oxygen.On his third day in hospital he was premedicated with 180 mg. of chloral hydrate and placed in the oxygen chamber. The pressure was raised to 23 lb./sq. in. (1-6 kg./cm.2), or 21 atmospheres absolute. He remained asleep, and after 10 minutes his toes became pink. He awoke after 60 minutes and the pressure was lowered at 75 minutes. The next day there were only a few new purpuric spots on his knees and he was given two further treatments of 75 minutes at 21 a...
