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

syndrome A syndrome is a set of medical signs and symptoms which are correlated with each other and often associated with a particular disease or disorder. The word derives from the Greek σύνδρομον, meaning "concurrence". When a syndrome is paired ...

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 Pneumomediastinum (from Greek ''pneuma'' – "air", also known as mediastinal emphysema) is pneumatosis (abnormal presence of air or other gas) in the mediastinum, the central part of the chest cavity. First described in 1819 by René Laennec, th ...

(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. There ...

), sometimes associated with pain and, less commonly,

dyspnea Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathing, breathe well enough. The American Thoracic Society defines it as "a subjective experience of brea ...

(difficulty breathing),

dysphonia A hoarse voice, also known as dysphonia or hoarseness, is when the voice involuntarily sounds breathy, raspy, or strained, or is softer in volume or lower in pitch. A hoarse voice, can be associated with a feeling of unease or scratchiness in the ...

, and a low-grade

fever Fever, also referred to as pyrexia, is defined as having a body temperature, temperature above the human body temperature, normal range due to an increase in the body's temperature Human body temperature#Fever, set point. There is not a single ...

. Hamman's syndrome can cause

Hamman's sign Hamman's sign (rarely, Hammond's sign or Hammond's crunch) is a crunching, rasping sound, synchronous with the heartbeat, heard over the precordium in spontaneous mediastinal emphysema. It is felt to result from the heart beating against air-filled ...

, 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, ''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 Barotrauma is physical damage to body tissues caused by a difference in pressure between a gas space inside, or contact with, the body and the surrounding gas or liquid. The initial damage is usually due to over-stretching the tissues in tensio ...

, 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