Hamman's syndrome, also known as Macklin's syndrome, is a syndrome of spontaneous

subcutaneous emphysema Subcutaneous emphysema (SCE, SE) occurs when gas or air accumulates and seeps under the skin, where normally no gas should be present. ''Subcutaneous'' refers to the subcutaneous tissue, and ''emphysema'' refers to trapped air pockets resembling t ...

(air in the

subcutaneous tissue The subcutaneous tissue (), also called the hypodermis, hypoderm (), subcutis, superficial fascia, is the lowermost layer of the integumentary system in vertebrates. The types of cells found in the layer are fibroblasts, adipose cells, and macr ...

s of the skin) and pneumomediastinum (air in the

mediastinum The mediastinum (from ) is the central compartment of the thoracic cavity. Surrounded by loose connective tissue, it is an undelineated region that contains a group of structures within the thorax, namely the heart and its vessels, the esophagu ...

, the center of the

chest cavity The thoracic cavity (or chest cavity) is the chamber of the body of vertebrates that is protected by the thoracic wall ( rib cage and associated skin, muscle, and fascia). The central compartment of the thoracic cavity is the mediastinum. Ther ...

), sometimes associated with pain and, less commonly, dyspnea (difficulty breathing), dysphonia, and a low-grade fever. Hamman's syndrome can cause Hamman's sign, an unusual combination of sounds that can be heard with a

stethoscope The stethoscope is a medical device for auscultation, or listening to internal sounds of an animal or human body. It typically has a small disc-shaped resonator that is placed against the skin, and one or two tubes connected to two earpieces. ...

Causes

The cause of Hamman's syndrome is most commonly unknown (idiopathic). Excessive duration and/or intensity of activities that mimic

valsalva manoeuvres The Valsalva maneuver is performed by a forceful attempt of exhalation against a closed airway, usually done by closing one's mouth and pinching one's nose shut while expelling air out as if blowing up a balloon. Variations of the maneuver can ...

, ''i.e.'' that increase intrathoracic pressure, can cause barotrauma, and hence pregnancy (and constipation and other causes of excessive straining) can be a precipitating cause of Hamman's syndrome. Indeed, it is estimated to occur in approximately 1 in 100,000 live births and is associated with prolonged labour times. Additionally, vomiting and coughing have also been noted as occasional precipitating factors. Hamman's is thus unsurprisingly occasionally known to be associated with asthma (''i.e.'' frequent coughing), excessive alcohol use (''i.e.'' frequent vomiting) and inhalational illicit substance use (such as cocaine use). Despite these associations, often, no precipitating cause is found.

Pathophysiology

Macklin described the pathophysiology of Hamman's syndrome to be barotrauma, whereby rupture of alveolar membranes causes a positive pressure gradient of air from the lungs into the mediastinum (the Macklin effect).

Diagnosis

Treatment

Treatment is supportive. Hamman's syndrome tends to be benign and self-limiting. It is important to differentiate it from far more serious conditions that have similar symptoms, such as

Boerhaave's syndrome Esophageal rupture is a rupture of the esophagus, esophageal wall. Iatrogenic causes account for approximately 56% of esophageal perforations, usually due to medical instrumentation such as an endoscopy or paraesophageal surgery. In contrast, the ...

History

It was named after clinician

Louis Hamman Louis Virgil Hamman (December 21, 1877 – April 28, 1946) was recognized as one of the great clinicians in his time. Early life Louis Virgil Hamman was born on December 21, 1877, in Baltimore, Maryland, to Agatha (née Haseneyer) and John A. Ha ...

, M.D.L. V. Hamman. Spontaneous mediastinal emphysema. Bulletin of the Johns Hopkins Hospital, Baltimore, 1939, 64: 1-21.

References

External links

{{chest trauma Respiratory diseases Chest trauma Syndromes