Typical Age Range for Infantile Colic
Infantile colic typically peaks at around 6 weeks of age and resolves by 3 to 4 months of age, making the first 3 months of life the characteristic period for this condition. 1
Clinical Timeline and Natural History
The evidence clearly establishes the temporal pattern of infantile colic:
- Crying begins in the first month of life, with duration increasing progressively until it peaks between 2 and 4 months of age 2
- Peak symptoms occur at approximately 6 weeks of age 1
- Symptoms resolve spontaneously by 3 to 6 months of age, with most cases resolving by the fourth month of life 3, 1, 4
Why This Matters for the Clinical Scenario
The 2-month-old infant in this case fits the classic presentation:
- Episodes began at 1 month of age (typical onset) 2
- Currently 2 months old (approaching the peak crying period at 6 weeks to 2-4 months) 2, 1
- Intense crying episodes lasting 1-2 hours, occurring 2-3 times per week (consistent with colic criteria) 1, 5
Diagnostic Criteria Context
Infantile colic is defined by the "Rule of Threes": paroxysms of inconsolable crying for more than 3 hours per day, more than 3 days per week, for longer than 3 weeks in an otherwise healthy infant 1, 5. This condition affects approximately 10-40% of infants worldwide, with equal incidence between sexes 1.
Critical Clinical Pitfall
While reassuring parents about the benign, self-limiting nature of colic is essential 5, 4, clinicians must recognize that crying is the most common trigger of abusive head trauma, with the incidence of abusive head trauma paralleling the normal developmental crying curve that peaks at 2-4 months 2. This makes anticipatory guidance and parental support during this period critically important for preventing child maltreatment.
Answer: C. First 3 months of life - This encompasses the typical onset (first month), peak (6 weeks to 2-4 months), and resolution (by 3-4 months) of infantile colic 2, 3, 1, 4.