Epidemiology & Risk Factors
Onset: Typically starts around 2-3 weeks of age, peaks at 6 weeks, and resolves spontaneously by 3-4 months.
Prevalence: Affects 10-40% of infants worldwide.
Risk factors: No correlation with infant sex, gestational age, socioeconomic status, or breastfeeding vs. formula-feeding.
Clinical Features
Rule of 3s : Crying that lasts >3 hours/day , occurs >3 days/week , for >3 weeks in an otherwise healthy and well-fed infant. c Paroxysmal episodes: Often occurs in the late afternoon or evening.
Associated signs: Grimacing, drawing up of legs, fists clenched, abdomen distended/tense, difficult to console.
Normal growth & development : Infant feeds well, gains weight appropriately, and is developmentally on track.
Diagnosis
Initial & Confirmatory : Clinical diagnosis based on history (Rule of 3s) and a completely normal physical exam (PE must rule out organic causes).Labs/Imaging: None indicated. Testing should be avoided unless red flags are present.
Red Flags (suggest organic pathology): Fever, lethargy, poor weight gain/failure to thrive, persistent vomiting, blood in stool, abnormal neurological signs.
Differential Diagnostics
Cow’s milk protein allergy : Differentiated by systemic signs such as painless bloody/mucoid stools , eczema, vomiting, or poor weight gain.Gastroesophageal reflux disease (GERD) : Differentiated by frequent spit-ups, poor weight gain, or Sandifer syndrome (back arching).Corneal abrasion : Differentiated by acute onset of crying, unilateral tearing, and diagnosis via positive fluorescein staining .Hair tourniquet : Differentiated by identifying a hair or thread wrapped tightly around a digit, penis, or uvula during a head-to-toe exam.Urinary tract infection (UTI) : Differentiated by fever, lethargy, poor feeding, and positive urinalysis/culture.Intussusception : Differentiated by episodic, severe, colicky pain associated with “currant jelly” stools , a palpable sausage-shaped mass, or lethargy.
Management
Reassurance & Education (First-line) :
Reassure parents that colic is benign, self-limiting, and not due to parental failure.
Provide a crying diary to track episodes and help parents identify patterns.
Soothing Techniques : c
Use rhythmic movement (rocking, car rides), swaddling, pacifiers, white noise, or a warm bath.
Review proper feeding techniques to minimize air swallowing (e.g., holding baby upright, frequent burping).
Dietary Trials (Select cases only) :
If milk protein allergy is suspected: 2-week trial of eliminating cow’s milk from maternal diet (if breastfed) or switching to hydrolyzed formula (if formula-fed).
Pharmacotherapy :
Avoid pharmacotherapy : Simethicone, lactase, and probiotics show no proven benefit over placebo.Contraindicated : Dicyclomine is contraindicated in infants <6 months of age due to serious risks (apnea, seizures, coma, death).
Complications
Abusive Head Trauma (Shaken Baby Syndrome) : High risk due to parental exhaustion and frustration.Postpartum depression (maternal or paternal).
Early, unintended cessation of breastfeeding.