Excessive and persistent crying
Also known as: Inconsolable crying, Infant colic
Excessive and persistent crying is crying or fussing that is longer, more frequent or more intense than the family expects, or that cannot be settled by the usual comforting. It is one of the commonest reasons for parents to seek help in the first 6 months of life. Most crying in a well infant is normal or due to infantile colic.
It is a major source of parental exhaustion, anxiety, postnatal depression and, in the worst cases, abusive head trauma. Crying can also be the only sign of serious illness:
- Sepsis, meningitis
- Intussusception, torsion, strangulated hernia
- Corneal abrasion, hair tourniquet, fracture
- Raised intracranial pressure, heart failure, supraventricular tachycardia
- Non accidental injury
Definitions. Normal crying rises from about 1 to 2 hours daily in the first 2 weeks to a peak of about 2 to 3 hours daily at 6 weeks. It then declines to about 1 hour daily by 3 to 4 months.
- Infantile colic: recurrent and prolonged periods of crying, fussing or irritability in an infant under 5 months. They occur without obvious cause and cannot be prevented or resolved by caregivers, in an otherwise healthy, well fed, thriving infant.
- The classic "rule of threes" describes crying for more than 3 hours daily, on more than 3 days each week, for more than 3 weeks.
- Persistent crying: crying that continues beyond 3 months or that is accompanied by feeding problems, poor growth or other symptoms.
- Inconsolable crying: crying that is not relieved by feeding, changing, holding or rocking.
- Abusive head trauma: brain injury from shaking or impact. Crying is its most common trigger.
Classification by cause
- Normal developmental crying and infantile colic (most common, 5% to 25% of infants, no organic cause).
- Hunger, thirst, wet or soiled nappy, temperature discomfort, tiredness and overstimulation.
- Gastrointestinal: gastro-oesophageal reflux disease and oesophagitis, cow's milk protein allergy, lactose overload, constipation, anal fissure, gastroenteritis, intussusception, malrotation with volvulus, incarcerated inguinal hernia, necrotising enterocolitis in preterm infants, and swallowed air.
- Infection: otitis media, urinary tract infection, meningitis, sepsis, oral thrush or herpetic gingivostomatitis, osteomyelitis and septic arthritis, bronchiolitis, and pneumonia.
- Trauma and mechanical: fractures (including non accidental), hair or thread tourniquet of a finger, toe or genitalia, corneal abrasion, foreign body, clothing or nappy pin injury, and sunburn.
- Surgical: testicular torsion, hernia, intussusception, and appendicitis in older children.
- Neurological: raised intracranial pressure, subdural haematoma, hydrocephalus, migraine in older children, kernicterus, neonatal abstinence syndrome, and hypoxic injury.
- Cardiac and metabolic: supraventricular tachycardia, heart failure, anomalous coronary artery, hypoglycaemia, hypocalcaemia, and inborn errors of metabolism.
- Drug and toxin related: maternal caffeine, nicotine or antidepressant exposure through breast milk, vaccine reaction, withdrawal, and medicines (decongestants, salbutamol).
- Parent and environmental factors: maternal anxiety or depression, difficult infant temperament, overfeeding, inconsistent responses, and smoke exposure.
- Older children: night terrors, separation anxiety, pain (growing pains, headache, dental, earache), behaviour and emotional disorder, abuse, bullying, and autism spectrum disorder with sensory overload.
Epidemiology. Infantile colic affects 10% to 20% of infants worldwide under common definitions. It starts at 2 to 3 weeks, peaks at 6 weeks and resolves in most by 3 to 4 months (90% by 5 months). It affects breastfed and formula fed infants equally.
Organic disease is found in under 5% of infants who present with crying and are otherwise well.
Crying is the leading trigger for abusive head trauma, with peak incidence at 2 to 3 months. The incidence of shaking is 14 to 40 in each 100,000 infants under 1 year in high income settings. Postnatal depression affects 10% to 20% of mothers and is more common when the infant cries excessively.
Mechanisms. Crying peaks at 6 weeks in all cultures, which supports a neurodevelopmental basis (immaturity of arousal and self settling). Proposed contributors to colic include gut immaturity and altered gut microbiota, visceral hypersensitivity, intestinal gas, serotonin and motilin changes, food protein sensitivity, and parent infant interaction. Pain, hunger, discomfort, illness and fear drive crying in all other causes.
Key distinctions.
- An infant under 3 months who is well between episodes, feeds and grows normally, has a normal examination and has evening predominant crying with a red face, drawn up legs and clenched fists points to colic.
- Sudden onset of inconsolable crying in a previously settled infant points to a new cause (hair tourniquet, corneal abrasion, hernia, torsion, injury, infection).
- Colicky bouts every 15 to 20 minutes with pallor, drawing up of the legs, vomiting and then "redcurrant jelly" stool point to intussusception.
- Crying with bile stained vomiting points to obstruction.
- Crying with fever, lethargy, poor feeding or a bulging fontanelle points to sepsis or meningitis.
- Crying with feeds, arching, vomiting and poor weight gain points to reflux disease or cow's milk protein allergy.
- Crying with eczema, blood or mucus in stool and vomiting points to cow's milk protein allergy.
- Crying with tachycardia over 220 beats/min, pallor and poor feeding points to supraventricular tachycardia.
