An 82-year-old woman presents with facial purpuric lesions that developed while she was hospitalized for an acute respiratory tract infection characterized by severe paroxysms of nonproductive cough and dyspnea. The lesions appeared suddenly and spontaneously and were not associated with trauma. The patient denies pruritus or pain and is otherwise well. The remainder of her physical examination is within normal limits. She has hypertension, diabetes, and hyperuricemia but has had no recent changes in her medications.
Q: What is the most likely diagnosis?
- Idiopathic thrombocytopenic purpura
- “Cough purpura”
- Purpura fulminans
- Actinic purpura
A: The correct answer is cough purpura, a benign and nonthrombocytopenic eruption that appears to be related to a sudden rise in the venous and capillary pressure in the head and neck caused by a rise in intrathoracic pressure during coughing.1–3 Physical examination shows erythematous, nonblanching macules, smaller than 1 cm, distributed on the face and neck.
Cough purpura is one form of the “mask phenomenon,”4 which is an unusual purpura of the relatively loose tissues of the face and neck occurring after vigorous vomiting, the Valsalva maneuver, parturition, prolonged coughing, or any other exertion that raises intrathoracic or abdominal pressure.1–5 The onset is acute. A workup for a coagulation or platelet defect is usually not required. Facial localization is unusual in most other forms of purpura, so its presence in addition to coughing should suggest cough purpura.
Recognizing cough purpura can help avoid misdiagnoses such thrombocytopenic purpura or purpura fulminans that could lead to ordering unnecessary tests, frightening the patient, and unnecessary confusion. The purpura fades spontaneously within 24 to 72 hours, and no treatment is needed.