Marasmus

Marasmus is the non-oedematous form of severe acute malnutrition, shown by severe wasting of fat and muscle after prolonged inadequate energy intake. The child appears extremely thin, with visible ribs and loose skin folds.

It is defined by a weight-for-length z-score under minus 3 or a mid-upper-arm circumference under 115 mm in children aged 6 to 59 months, with no bilateral oedema. It occurs in settings of poverty, famine, early weaning and recurrent infection, and in chronic disease such as HIV, malabsorption and cardiac or neurological disease.

Pathophysiology.

Prolonged energy deficiency causes adaptation: reduced metabolic rate, loss of subcutaneous fat and muscle for fuel, and reduced organ size. The heart, kidney and gut function are impaired, with reduced reserve to cope with infection, fluid and electrolyte load.

Protein, vitamin and mineral deficiencies compound immune dysfunction, so infection is frequent and may be atypical, without fever.

• Severe wasting with visible ribs, wrinkled "old man" face, sunken eyes, and loose skin over the buttocks and thighs.
• Irritable or apathetic child, hungry in early disease and anorexic later.
• Hypothermia, hypoglycaemia, bradycardia, low blood pressure and dehydration (difficult to assess because of loose skin and sunken eyes).
• Stunting and developmental delay in prolonged disease.

Red flags.

• Lethargy, unconsciousness, hypoglycaemia (glucose under 3 mmol/L), hypothermia or shock.
• Severe pallor, jaundice, cough with fast breathing, or eye signs of vitamin A deficiency.
• Failed appetite test or inability to feed.

• Anthropometry: weight-for-length z-score, mid-upper-arm circumference and length or height, and check for oedema of both feet.
• Appetite test with ready-to-use therapeutic food to separate complicated from uncomplicated disease.
• Blood glucose, malaria test where relevant, HIV test, full blood count, urinalysis and culture, chest X-ray, tuberculosis assessment, and stool examination.
• Search for the underlying cause: chronic infection, malabsorption, congenital heart disease, neglect or feeding problems.

Differential diagnosis. Chronic infection (HIV, tuberculosis), malabsorption (coeliac disease, cystic fibrosis), congenital heart disease, inborn errors of metabolism, endocrine disease, chronic kidney disease and neglect.

Stabilisation phase (days 1 to 7).

• Treat hypoglycaemia with 10% glucose 5 mL/kg IV or oral glucose, then feed every 2 to 3 hours. Warm the child and treat hypothermia.
• Feed with low lactose therapeutic milk providing 75 kcal for each 100 mL, at 100 kcal/kg/day, in small frequent feeds by cup or nasogastric tube.
• Dehydration: use low sodium rehydration solution 5 mL/kg every 30 minutes for 2 hours, then 5 to 10 mL/kg/h for up to 10 hours, alternating with feeds. Use IV fluids only for shock, 15 mL/kg of compound sodium lactate solution in 5% glucose over 1 hour, reviewed after each bolus.
• Antibiotics: amoxicillin 15 mg/kg orally every 8 hours for 5 days. For complicated disease, ampicillin 50 mg/kg IV every 6 hours with gentamicin 7.5 mg/kg IV once daily for 7 days.
• Micronutrients: potassium 3 to 4 mmol/kg/day, magnesium 0.4 to 0.6 mmol/kg/day, zinc 2 mg/kg/day, copper 0.3 mg/kg/day, folic acid 5 mg on day 1 then 1 mg daily, and vitamin A for eye signs. Withhold iron initially.
• Transfuse only for haemoglobin under 40 g/L or under 60 g/L with respiratory distress, giving 10 mL/kg of packed red cells slowly and without routine furosemide.

Rehabilitation phase.

• Change to therapeutic milk providing 100 kcal for each 100 mL or ready-to-use therapeutic food to reach 150 to 220 kcal/kg/day. Start iron 3 mg/kg/day once appetite is established.
• Prevent refeeding complications: monitor potassium, magnesium and phosphate, and avoid rapid advancement.
• Play, stimulation and caregiver counselling. Continue outpatient care until weight-for-length is over minus 2 z-scores.

Monitoring. Daily weight, temperature, pulse, respiratory rate and feed intake. Monitor for heart failure and refeeding syndrome. Weight gain over 5 g/kg/day shows recovery.

Referral and escalation. Admit children with complications or poor appetite. Investigate the underlying disease if there is no response in 2 weeks.

Special groups. Infants under 6 months need breastfeeding support and inpatient care. Children with HIV need antiretroviral therapy started once they are clinically stable.