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history, and physical examination, together with a limited number of ancillary
tests, may help establish the specific diagnosis.
Suggested Readings and Key References
Davitt M, Delvecchio MT, Aronoff SC. The Differential diagnosis of vertigo in
children: a systematic review of 2726 cases. Pediatr Emerg Care 2017;1–4.
MacGregor DL. Vertigo. Pediatr Rev 2002;23:10–16.
Phillips JO, Backous DD. Evaluation of vestibular function in young children.
Otolaryngol Clin North Am 2002;4:765–790.
Riina N, Ilmari P, Kentala E. Vertigo and imbalance in children. Arch Otolaryngol
Head Neck Surg 2005;131:996–1000.
Tusa RJ, Saada AA, Niparko JK. Dizziness in childhood. J Child Neurol
1994;9:261–274.


CHAPTER 25 ■ EDEMA
JAMES F. LEONI, ELAINE K. FIELDER

INTRODUCTION
Edema is defined as the abnormal swelling of tissues from the accumulation of
fluid in the extravascular space. This fluid may appear as generalized or localized
swelling. Frequently in pediatrics, edema occurs as a localized response to injury
or inflammation and, in this setting, is often benign and self-limited. However, it
is important to recognize that edema may be the result of a variety of causes and
the initial presentation of generalized edema may be quite subtle. When
significant edema is present, collections of fluid may be visualized as pericardial
or pleural effusions, or as ascites. When edema is profound and generalized, the
patient is described as having anasarca. The completion of a careful history and a
thorough physical examination will not only help to identify these patients early,
but may also lead to a definitive diagnosis in some cases.

PATHOPHYSIOLOGY

The occurrence of edema in healthy individuals is usually prevented by the
balance of oncotic and hydrostatic pressures between the intravascular and
interstitial spaces, as well as the normal function of the lymphatic system. Any
imbalance in this system may lead to increased interstitial fluid and eventual
tissue swelling. Edema may occur as a result of decreased intravascular oncotic
pressure, increased vascular permeability, increased hydrostatic pressure,
lymphatic dysfunction, or a combination of these factors.
Tightly controlled levels of circulating proteins, especially albumin, maintain
normal intravascular oncotic pressure. Hypoalbuminemia may arise from the
decreased production of proteins caused by hepatic disease, as a result of protein
malnutrition or, more commonly, from losses of protein through gastrointestinal,
renal, or dermal conditions. When the albumin level decreases, the oncotic
pressure in the vascular space is reduced and fluid can begin to move freely into
the soft tissues. If not corrected, generalized edema may result.
Edema can also result from changes in vascular (capillary) permeability,
mediated by mast cell release of histamines, IgE, and compliment cascade. This is
seen most commonly in patients with burns, sepsis, or hypersensitivity reactions.
In certain cases, the swelling may be rapid, localized, and potentially lifethreatening. In patients with a severe allergic reaction, such as that associated


with anaphylaxis, this edema may involve the tissues adjacent to the airway
leading to potential airway compromise.
When intravascular albumin levels are within the normal range and vascular
permeability is preserved, edema can result from increased hydrostatic pressures
that overcome the oncotic pressure, forcing fluid out of the vascular space. This
can occur as a result of changes in sodium and water retention from cardiac
failure, renal failure or estrogen–progesterone excess, or from venous obstruction.
Lymphatic dysfunction, either congenital or acquired, can also result in edema.

DIFFERENTIAL DIAGNOSIS

A myriad of disease processes can result in either localized or generalized edema
( Table 25.1 ). Localized edema in children is often caused by an allergic
reaction, with the most severe reactions resulting from exposure to nuts, shellfish,
or hymenoptera venom. Idiopathic nephrotic syndrome, although rare (occurring
in 4.7 of every 100,000 children annually), is the most common cause of
generalized edema ( Table 25.2 ). Overall, most children who develop edema will
have a benign diagnosis and a self-limited course. However, potentially lifethreatening conditions ( Table 25.3 ) causing edema can also occur, including
severe allergic reactions, sepsis, venous thrombosis, and kidney, liver, or cardiac
disease.

EVALUATION
When evaluating the child with edema it is necessary to obtain a thorough history
and perform a complete physical examination, including the assessment of vital
signs. It is important to remember that the onset of symptoms is often gradual and
subtle for causes of generalized edema. In fact, significant weight gain may be
accumulated, with symptoms existing for weeks to months, before a patient
presents for medical care. It is, therefore, essential to inspect for edema around
the eyes, scrotum or labia, as well as the distal extremities, as these areas may be
the only locations with perceptible swelling.
It is also helpful to classify the swelling as localized or generalized ( Fig. 25.1 )
and to determine the location of the edema (facial vs. extremities), as well as any
associated symptoms including fever, shortness of breath, pain, or recent illness.
The duration of the symptoms and the patient’s age may help to narrow down the
potential diagnoses, as certain disorders will present in the newborn period
(congenital lymphedema, Turner syndrome) while others occur more frequently
in school-age children or adolescents (nephrotic syndrome, vasculitis). A
thorough medical history, including a dietary history and a family history, is
helpful to identify patients with chronic conditions, such as protein malnutrition,

or inherited disorders, such as hereditary angioedema. Current and recent
medications and allergies may also assist in clarifying the diagnosis.

LOCALIZED EDEMA
Localized edema is a more common presenting complaint in pediatrics than
generalized edema. Usually, areas of localized swelling are caused by minor
trauma, infection, or secondary to an allergic reaction. Historical factors and
physical examination findings will often lead to a particular diagnosis without the
need for further testing. Tenderness to palpation and associated hematoma points
to trauma, while fever, erythema, and overlying warmth more commonly occur
with an infectious cause. On the face and distal extremities, insect bites may
produce swelling and warmth, which can be difficult to distinguish from
cellulitis. A therapeutic response to an oral antihistamine or to an intramuscular
dose of epinephrine can help to differentiate an allergic reaction from other
causes of localized swelling.