Doctor, I am sweating on just one side of my body: unilateral hyperhidrosis associated with mesothelioma.

Unilateral hyperhidrosis is rare and should prompt a thorough review for potentially serious underlying etiologies. Available treatments for unilateral hyperhidrosis secondary to mesothelioma are limited and its presence as a symptom usually signifies advanced disease and a poor prognosis.

Question: Can you name some possible causes for the image demonstrated?

Answer: The potential differential diagnosis for unilateral hyperhidrosis should include hypothalamic tumors, cerebral infarction, encephalitis, syringomyelia, trauma, neuritis, cervical rib, and intrathoracic malignancy.

A 55‐year‐old man with a childhood history of asbestos exposure presented with left‐sided chest pain. CT imaging suggested pleural‐based soft tissue deposits, including one in the left aorto‐vertebral recess. Biopsy was diagnostic of malignant mesothelioma of sarcomatoid type. Disease progression despite radiotherapy and chemotherapy was associated with the development of profound hyperhidrosis on the contralateral side. No new right‐sided paravertebral disease was evident on repeat staging (Fig. 1). Figure 2 demonstrates the outcome of the Minor sweat test.

Figure 1

Contrast CT of the chest demonstrating a soft tissue mass in the L aorto‐vertebral recess.

Figure 2

Iodine was applied to the skin of the trunk and allowed to dry. Cornflour was applied. The hyperhidrotic area turned from yellow to violet/dark blue. This image was captured after 5 min in humid conditions. It shows unilateral hyperhidrosis on the contralateral side of the lesion. Please note, for patient comfort the test was administered on only a small portion of the back.

Unilateral hyperhidrosis secondary to underlying intrathoracic malignancy has rarely been reported in the literature. To explain contralateral hyperhidrosis in the event of ipsilateral damage to the sympathetic chain, Brodoehl et al. have suggested a loss of negative feedback on the hypothalamus (resultant in increased positive feedback and sweating on the contralateral side) 1. Unilateral hyperhidrosis in mesothelioma usually signifies advanced disease and has a poor prognosis 2.

Conflict of Interest

None declared.

Ethical Approval

The relevant institution does not require ethics approval. The manuscript conforms to standards currently applied in Australia.

Consent

Consent is provided in the format used by the BMJ. The patient has read the final document and indicated as such on the provided consent form. In addition, the manuscript has been completely anonymised.