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Original case report; renal biopsy showed tubular injury with refractile calcium oxalate crystals. The case does not establish that every exposure produces hypocalcaemia. Indexed full text was available; direct retrieval intermittently displayed a browser-verification page.

Oxalic acid poisoning may produce corrosive gastrointestinal injury, early circulatory collapse and later kidney injury; no single post-mortem appearance proves the diagnosis. The severity of local injury and systemic poisoning need not be identical in every case.

After ingestion, burning pain in the mouth, throat or upper abdomen may be followed by vomiting, sometimes containing blood, abdominal tenderness and diarrhoea. Weakness, a small rapid pulse, cold clammy skin and collapse may develop. A dilute preparation may produce less obvious surface injury than concentrated oxalic acid, while still giving systemic poisoning. Current chemical safety information recognizes both corrosive effects and disturbance of calcium balance.^[ref]

The absorbed oxalate can bind calcium and form calcium oxalate. A fall in ionized calcium can contribute to neuromuscular disturbance and cardiac instability, but hypocalcaemia must not be asserted to occur in every case or inferred from a symptom alone. If the person survives the early illness, acute kidney injury can follow. In modern pathological investigations, calcium oxalate crystals in renal tubules and associated tubular damage provide a mechanism for this later complication.^[ref][ref]

At autopsy, examine the mouth, oesophagus and stomach for corrosive changes. Depending on concentration and survival, the mucous membrane may be pale or discoloured, inflamed, eroded, haemorrhagic or softened; blood-stained contents and severe gastric damage may be present. Perforation is possible, but is not a necessary finding. The pre-examination report Case of Criminal Poisoning with Oxalic Acid, in Which Perforation of the Stomach Took Place by Henry Duncan Littlejohn documents a particular severe example with marked softening and perforation. It is evidence that these changes can occur, rather than a description that every fatal case must reproduce.^[ref]

Examine the kidneys as well as the gastrointestinal tract; histological tubular changes and crystals may matter especially after delayed death. Nevertheless, calcium oxalate deposition is not unique to direct ingestion of oxalic acid, and gross corrosive damage is not unique to this poison. Preserve material for controlled toxicological analysis, and interpret the chemical findings alongside the history and pathological distribution. The older classification of oxalic acid as a “narcotic” does not adequately explain the corrosive, electrolyte and renal mechanisms now recognized.

Discuss paralysis and convulsions separately: both historical labels describe manifestations with several causes. Their occurrence in infancy does not establish one diagnosis, and neither permits invention of examination findings absent from the paper.

For infantile paralysis, distinguish an acute loss of movement after an illness from impaired movement present from birth, delayed motor development and progressive weakness. Note distribution, muscle tone, tendon reflexes, sensation, pain, muscle atrophy, and bulbar or respiratory involvement. The classic acute flaccid, often asymmetric syndrome later identified with poliomyelitis must be distinguished from cerebral injury, cerebral palsy, peripheral nerve injury, spinal disease and painful failure to move a limb. A child who avoids movement because it hurts has pseudoparalysis, not necessarily loss of motor innervation.

An 1866 explanation might attribute some cases to teething, chill or constitutional weakness, and use rubbing, warmth, supports or electrical stimulation. Such attributions need qualification: a preceding event does not prove the mechanism, and electrical contraction does not demonstrate restoration of damaged motor neurons. The clinically useful period aims were preservation of comfort, nutrition and limb position and prevention of deformity while following recovery. No historical stimulant can be assumed to regenerate destroyed neural tissue.

Modern correction: acute weakness requires urgent localization and evaluation of breathing and swallowing. Poliomyelitis results from poliovirus infection and can permanently damage motor function; there is no specific curative treatment for paralytic disease. Supportive care and appropriate rehabilitation address respiratory risk, function and complications; vaccination is preventive rather than a reversal of established paralysis.^[ref] Cerebral palsy describes a different developmental motor disorder associated with disturbances of the developing brain; assessment, investigation when appropriate, physiotherapy, occupational support and treatment of associated problems are individualized. Not every case is attributable to a single event during delivery, and loss of previously attained abilities requires reconsideration of a static diagnosis.^[ref]

For infantile convulsions, consider fever, meningitis, encephalitis, hypoglycaemia, hypocalcaemia and other metabolic disorders, head injury, structural cerebral disease, toxic exposure and epilepsy. Clarify the age, duration, whether movements are focal, recovery between attacks and the child's condition before and afterwards. Neonatal seizures and convulsions in an older febrile infant should not be collapsed into one reassuring category. “Teething” is not a satisfactory explanation for a serious seizure, and a warm bath or gum-lancing must not replace investigation.

During an attack, protect the airway and prevent injury; do not put objects or oral medicines into the mouth. Assess breathing and circulation, time the event, check blood glucose promptly and identify reversible causes. A convulsive seizure lasting five minutes or more is a medical emergency requiring resuscitation and a current status epilepticus pathway, beginning with an appropriate benzodiazepine and escalating if needed. Hypoglycaemia, infection and electrolyte disturbances need direct treatment as well as suppression of movements.^[ref][ref] Following the event, investigate the cause and arrange appropriate follow-up; one provoked convulsion does not by itself establish chronic epilepsy.