Chromhidrosis is a rare sweat gland disorder characterized by the excretion of colored sweat.1 It can be classified as apocrine, true eccrine, or pseudochromhidrosis.2 Apocrine chromhidrosis is characterized by oxidized lipofuscin granules in the apocrine sweat glands whereas eccrine chromhidrosis is secondary to water-soluble pigments excreted in sweat. Pseudochromhidrosis is a condition in which although normal colorless sweat is excreted, it turns into a different color after contact with chromogenic microbial products or extrinsic chemicals.2–5

A 78-year-old woman with a history of prediabetes on metformin presented to endocrinology clinic 2 days after receiving a booster shot of BNT162b2 (Pfizer, Inc) COVID-19 vaccine. She noticed a grayish tint on her fingernails (Figure 1) and blue stains on her white pillowcase, washcloth, and sheets (Figure 2, 3) associated with sweat production. When she removed her clear nail polish, the cotton ball was blue-stained. She had a similar episode after she received a previous dose of the same COVID-19 vaccine. She denied the use of quinines, bisacodyl, rifampin, or coloring substances in her food. There was no history of exposure to heavy metals or symptoms suggestive of fungal infection. She reported this event to the vaccine manufacturer. A skin biopsy was not performed to evaluate for lipofuscin granules. Her symptoms resolved without intervention upon 3 month follow up. Further studies are necessary before making an association between this rare condition and COVID-19 vaccination.

Figure 1
Figure 1.Grayish tint in her nails
Figure 2
Figure 2.Blue-black stain on her washcloth
Figure 3
Figure 3.Bluish-black pigmentation in her pillowcase

Corresponding author

Maun R. Baral, MD
Resident Physician
Maun.rbaral@gmail.com
ORCiD: 0000-0002-5810-6751
Tel: 2038376079
Danbury Hospital,
24 Hospital Avenue
Danbury, CT, 06810, USA

Author Conflicts of Interest

No disclosures or conflicts of interest