Irritability and intractable crying may be the presenting complaint for a wide range of medical problems in infants and children, some of which are potentially serious. Recently it has been estimated that 5% of infants presenting to the emergency department with crying have a serious underlying illness and two-thirds of these cases may be identified through careful history and physical examination.¹ Symptoms may also begin after hospitalization. Hospital providers must be able to differentiate significant irritability and intractable crying from developmentally appropriate crying. They must be familiar with the common causes of irritability and intractable crying as well as the more unusual causes and a stepwise approach to evaluation.

Irritability is a state of increased sensitivity to stimuli; it may also be described by parents as fussiness, whining, or increased crying. Crying is the primary way that infants and young children express hunger, thirst, fear, fatigue, desire for attention, and discomfort or pain. When caregivers have taken the usual measures to address these common needs, such as feeding and holding the child and changing the diaper, yet the child continues to cry, the child is said to be inconsolable or to have intractable crying.

The quantity as well as the quality of crying behavior should be considered. What qualifies as excessive crying varies based on the age and developmental level of the child, as well as the clinical scenario. Normal infants cry most during the first 3 months of life; during this period, serious illness may present with few or only subtle signs and symptoms, making evaluation in this age group particularly challenging.

Crying should also be evaluated to determine whether it is appropriate for the clinical scenario. For example, a febrile infant with a viral upper respiratory infection is likely to be irritable and may cry more than usual. However, crying with movement of the child’s lower extremities should lead to suspicion of an alternative cause, such as meningitis or a septic hip joint. Stranger anxiety—which appears at around 8 to 9 months of age, peaks at 12 to 15 months, and decreases thereafter—may manifest as inconsolable crying during examination; however, an otherwise healthy child should be comforted and calmed in the arms of a caregiver.

A change in the character of a child’s cry may also be significant: louder, higher pitch, or more urgent tone or a weak, stridulous, or hoarse cry may suggest the presence of illness.

PATHOPHYSIOLOGY

Irritability may result from pain, discomfort, or fatigue, direct neurologic insult, or altered metabolic or endocrine status. Crying in infants and young children is an involuntary action that serves physiologic and protective purposes. A newborn’s first cries enable essential changes in the cardiorespiratory system during the transition to postnatal life. Crying increases to almost 3 hours per day, on average, by 6 weeks of life and decreases thereafter. During this period of greatest crying, infants cry most during the late afternoon and evening hours, perhaps to release tension accumulated throughout the day from internal and external stimuli and maintain homeostasis. Crying is also a way for infants and children to express their emotional needs.

It is important to obtain a detailed description of the irritability and crying, as delineated in Table 29-1. Note history of associated symptoms, including fever, malaise, feeding difficulty, respiratory symptoms, vomiting or bilious vomiting, stool patterns and composition, parents’ perception of the source of pain, limping or joint irritability, skin irritation or redness, poor weight gain, and developmental delay or regression.

When examining the child, it is often helpful to observe respiration, movement, and behavior from across the room at first. This provides useful information and helps eliminate the confounding influences of stranger anxiety. With a frightened toddler, the parents can assist in the physical examination by exposing areas of skin and moving the extremities to check for tenderness while the examiner stands back several feet and observes. Use of distraction techniques can facilitate a complete physical examination. It is essential to examine the child from head to toe, fully exposed (removing clothes, shoes, socks, bracelets, barrettes, and so forth). Growth parameters, including head circumference in infants, should be assessed.

Because of the extensive differential diagnosis, a stepwise approach is essential. The presence of fever makes an infectious cause more likely; other inflammatory processes and endocrine disorders must also be considered. It is important to remember that serious bacterial infections can be present in the absence of fever, particularly in neonates, and may also coexist with more benign conditions such as viral upper respiratory tract infections. Most common causes of irritability and intractable crying in afebrile patients are apparent after a careful history and physical examination. A period of observation may also be helpful.

Bruising in perambulatory infants, particularly over the ears, facial injuries, limb swelling, or other signs of unexplained injury should raise concern for abuse. Evaluation for the presence of rib bruising or crepitus, a bulging fontanelle, and retinal hemorrhages should be included.

Care must be taken not to routinely attribute irritability and crying to otitis media. In older infants with intact tympanic membranes, determining whether otitis media observed on physical examination is the cause of the symptoms can be accomplished by placing anesthetic drops in the affected ear and observing the patient’s response. If the irritability does not dramatically improve, another cause should be sought.

Scrotal swelling that may or may not be tender may be seen with incarcerated inguinal hernia. Parents may not notice the presence of a hair tourniquet around an appendage such as a digit, penis, or clitoris, which can cause swelling, ischemia, and pain. The band of hair may not be visible if it is buried beneath a fold of edematous tissue. In some cases, the hair may be so tightly wound that it is difficult to release, making it necessary to remove the hair. Applying a hair removal cream, such as Nair, to the affected area for about 10 minutes may dissolve the hair and relieve the constriction.