Hamman syndrome

Hamman syndrome, also known as Macklin syndrome, refers to spontaneous pneumomediastinum along with subcutaneous emphysema.

Epidemiology

It is a rare entity most often encountered in young adults. It is a known entity peri- and postpartum ³.

Clinical presentation

The condition is most commonly asymptomatic. Presenting symptoms can include:

• non-specific chest pain 
• dyspnea
• dysphonia
• subfebrile temperature

Interestingly, possible signs on clinical examination include the Hamman sign, a pulse-synchronous rasping sound which is believed to be caused by pneumopericardium.

Pathology

Most commonly idiopathic (i.e. cryptogenic) in nature. The pathomechanism is barotrauma (see main article: Macklin effect). This is accounted for by the increased intrathoracic pressure associated with asthma and the peripartum period.

Radiographic features

See main article: pneumomediastinum. In rare cases, pneumorrhachis may also be encountered.

History and etymology

The syndrome is named after clinician Louis Virgil Hamman (1877-1946), who described it in 1939 ¹.

Differential diagnosis

It has to be distinguished from more sinister pathology or entities, e.g. Boerhaave syndrome, as the clinical course of Hamman syndrome is usually benign and self-limiting, and as such management is often conservative ³.

See also

• Boerhaave syndrome
• Macklin effect
• Hamman-Rich syndrome