Chlorotrichosis, commonly known as "green hair," is an uncommon trichological condition characterized by the accumulation of exogenous copper in people with blond hair. It is predisposed by damage to the hair cuticle.

The first cases of chlorotrichosis were described in 1654. At that time, the owners of green hair were coppersmiths who worked in copper processing. Today's chlorotrichosis patients are hapless pool-goers.

Today, the most common cause of this unusual disease is direct contact with household tap water with high copper content. Using copper-based algicides in swimming pools also increases the copper content of the water. Other causes of green hair have been reported related to the work of metal workers or the administration of serum containing dipyridamole.

Researchers from Mexico have published a clinical case of spontaneous green hair coloring in a 16-year-old girl. The hair color began to change after regular visits to the swimming pool. Clinical examination revealed a characteristic greenish coloration, primarily of the distal parts of the hair. The diagnosis of chlorotrichosis was confirmed based on clinical manifestations and history. Treatment included using a shampoo containing ethylenediaminetetetraacetic acid (EDTA), resulting in significant pigmentation regression within 8 weeks. In addition, preventive measures in the form of applying an ammonium-enriched conditioner before visiting the swimming pool were carried out [1].

Previously, a similar case was described by Spanish scientists [2]. A 20-year-old woman sought medical help due to the appearance of non-uniform coloration of some parts of her hair after swimming in an outdoor public pool. A study of the pool water composition showed that pH and chlorine levels were within the permissible limits, while copper concentration was 3 times higher than usual. As it turned out later, the swimming pool had been partially replaced for 7 years.

The patient's natural hair color was light brown. The distal third of her hair was colored green. The patient reported that a few days before the onset of chlorotrichosis, she had self-bleached the distal third using a commercial hair dye. Electron microscopy showed detachment of the hair cuticle layer with a wholly exposed cortex, particularly pronounced in the distal third of the hair. Remarkably, X-ray microanalysis revealed elevated silicon, aluminum, and iron content in the hair of the distal third with a complete absence of copper. According to the authors' assumptions, the cause of green hair coloration, in this case, was the reaction of excess copper in the pool with hair dye components containing hydrogen peroxide, resorcinol, phenylenediamines, and ammonia.

A previous publication concluded that chlorotrichosis causes the most damaged hair to be colored more intensely green. In this case, the hair damage occurred during coloring with a commercial dye.

Chlorotrichosis is quite rare. Patients often do not seek medical help, solving the problem at the hairdresser's shop.

Pseudogreen hair coloring requires a combination of two factors — the damaged condition of the hair and the presence of elevated copper content in the environment with which the hair comes in contact. So, keep your hair healthy, visit reputable swimming pools, and you will be safe from chlorotrichosis.

References

1. Tomas X., Nogueras M., Bartolome A., Ferrando J. Pseudo Green Hair. Int J Trichology 2022; 14(2): 65-67.
2. Lomelí-Legaspi E., Corona-Rodarte E., Enrique Cano-Aguilar L., et al. The greening of hair: a unique case of chlorotrichosis and its management. Skin Appendage Disord 2024; June: 1–4.