Why would a person have pink sweat (chromhidrosis)?

Pink sweat is typically due to chromhidrosis (colored sweat).

What is chromhidrosis?

Chromhidrosis is a rare condition characterized by the secretion of colored sweat. Approximately 10% of normal people have colored sweat (without chromhidrosis).

Two glands produce sweat:

- Eccrine glands secrete a clear, odorless fluid that regulates body temperature.

- Apocrine glands secrete a thick, milky sweat that, once broken down by bacteria, is the main cause of body odor (smell).

Which glands are responsible for chromhidrosis?

- Chromhidrosis is caused mainly by the apocrine glands. They are located in the genital, axillary, areolar, and facial skin. Chromhidrosis is reported only on the face, axillae, and breast areola.

- Eccrine chromhidrosis is rare and occurs with ingestion of certain dyes or drugs.

- Pseudochromhidrosis occurs when clear eccrine sweat becomes colored on the surface of the skin as a result of extrinsic dyes, paints, or chromogenic bacteria.

What is the pigment in chromhidrosis?

Lipofuscin is a yellowish brown pigment that is responsible for the colored sweat. Lipofuscin is produced in the apocrine glands, and its various oxidative states account for the characteristic yellow, green, blue, or black secretions in chromhidrosis.

Are any lab tests indicated?

No laboratory abnormalities are typically found in apocrine chromhidrosis. The following test may help to rule out other causes:

- complete blood cell count (CBC) to exclude bleeding diathesis
- urinary homogentisic acid levels to exclude alkaptonuria
- fungal and bacterial cultures to exclude infectious causes of pseudochromhidrosis

How to treat chromhidrosis?

Apocrine chromhidrosis has no cure. Patients can manually or pharmacologically empty the glands to remove the color for 48-72 hours (until the glands replenish the pigment).

Botox® injections have been attempted in chromhidrosis, with mixed results. Botox is predominantly used to decrease eccrine sweat in persons with hyperhidrosis.

Capsaicin cream (alkaloid found in chilly peppers) also can help.

References:

Chromhidrosis - Medscape http://bit.ly/UmhTXU
Facial and axillary apocrine chromhidrosis http://bit.ly/UmhV1Q
Treating Chromhidrosis - Discovery Health http://bit.ly/UmhVPE
Image source: Sweat, Shaylor's photostream, Creative Commons license. The image is not related and does not show a patient.

Comments from Twitter:

Laura VR Bertotto @LauraAtVMV: Botox has worked well for hyperhydrosis. This is interesting.

Dr. Claudia Aguirre @doctorclaudia: Interesting.