Severe Acute Malnutrition: Recognition and Management of Marasmus and Kwashiorkor

Severe acute malnutrition (SAM) is a life-threatening condition affecting millions of children worldwide and is characterized by inadequate weight relative to height. SAM is clinically categorized into 2 primary forms: marasmus, caused by an overall calorie deficiency, and kwashiorkor, primarily due to severe dietary protein deficiency despite adequate or near-adequate energy intake. A mixed form, marasmic-kwashiorkor, may also occur, combining features of both. The term "kwashiorkor" is derived from the Ga language spoken in Ghana and loosely translates to "the sickness a baby gets when the new baby comes," referring to early weaning to a low-protein, high-carbohydrate diet. Anthropometry, the measurement of a child's physical size and dimensions, is the most commonly used tool to quantify pediatric undernutrition. Children with the marasmus form of SAM exhibit severe wasting, defined by a weight-for-height z-score that is greater than 3 standard deviations below the mean, based on age and gender, or, in children aged 6 to 59 months, a mid-upper arm circumference of 115 mm or less. The World Health Organization (WHO) and the Centers for Disease Control and Prevention growth charts are the most frequently used references for growth standards (see . World Health Organization Classification of Weight Status Table). Children with severe wasting exhibit a marked loss of both fat and muscle mass. Those with kwashiorkor present with bilateral edema, often with minimal or no visible wasting.  Children with both forms of SAM typically have concomitant micronutrient deficiencies, particularly of iron, zinc, vitamin A, and iodine, which are associated with faltering growth, impaired cognitive development, and compromised host defenses, resulting in an increased risk of severe infections and mortality. Understanding these conditions' distinct presentations and underlying pathophysiology is critical for timely diagnosis and effective management. This article reviews the etiology, epidemiology, clinical features, diagnosis, and management of marasmus and kwashiorkor within the broader context of SAM, guided by WHO criteria and evidence-based clinical practice.