Safe Hair Care Can Prevent Trichorrhexis Nodosa

Trichorrhexis nodosa (TN) can be remedied through appropriate use of cleansing products, hair care and styling practices, new research suggests.

The findings are published ahead of print in the Journal of Dermatological Treatment.

TN Risk Factors Defined

Researchers from Johns Hopkins School of Medicine in Baltimore found that thermal styling tools, such as the use of flat irons and blow dryers, as well as chemical processing, such as permanent dye and straightening, tend to damage the cuticle. This can alter the hair's protein structure, which causes the cortical fibers to be exposed and fray, leading to weak points where breakage occurs.

Patients of African heritage (African-American and Afro-Caribbean) who tend to have tightly coiled hair are at increased risk for hair loss and damage from TN due to structural differences within the hair shaft. African hair fibers have an asymmetric shape and curvature, resulting in points of geometric weakness in the hair shaft. Curly hair also has differences in hydration properties, causing it to be drier and more susceptible to breakage.

Inadequate cleansing of the hair and scalp can result in the buildup of product residue, leading to problems such as seborrheic and irritant dermatitis.

TN Prevention and Treatment

The investigators also describe simple over-the-counter, nonmedical remedies that can be recommended by dermatologists when treating patients with TN.

First, choosing the appropriate shampoo based on hair types is incredibly important when trying to reduce breakage and loss. There are three types of surfactants to look for when selecting a shampoo -- anionic, amphoteric and nonionic. Anionic surfactants tend to be best suited for those with oily hair and are very effective at cleansing the hair, but this can leave the hair feeling dry and prone to breakage. Nonionic or amphoteric surfactants are recommended for those with natural black hair or dry, damaged or color-treated hair. These types of shampoos are gentler and less likely to strip the hair of moisture.

Second, the frequency at which the hair is cleansed is key in minimizing the impact of TN. Frequency varies greatly based on many factors, such as age, ethnic origin and condition of the hair. Those with tightly curled hair types should shampoo their hair less frequently, since sebum has a harder time coating this particular type of hair strand. Patients with straight hair should shampoo more frequently because sebum coats the entire strand, leading to oily hair.

"Patients with dry, damaged or tightly curled hair should limit their shampooing to no more than once per week. Those with straight hair, however, can shampoo daily," says Crystal Aguh, MD, assistant professor of dermatology at the Johns Hopkins University School of Medicine and co-author of Fundamentals of Ethnic Hair: The Dermatologist's Perspective, in a news release.

Third, conditioning the hair is arguably one of the most important steps for a healthy hair regimen. Conditioners increase hair manageability, help eliminate static electricity and can temporarily mend hair shaft damages. They come in many different formulations depending on the desired effect -- rinse-out, deep, leave-in and protein-containing.

Rinse-out conditioners are less effective in repairing hair damage due to their short contact time with the hair. Deep conditioners are beneficial for severely damaged hair. Leave-in conditioners are ideal for preventing damage from everyday grooming.

The most beneficial conditioning treatment for those with dry and damaged hair is protein-containing conditioners. These can be formulated as rinse-out, deep or leave-in. Though protein-containing treatments help with breakage, it is recommend to only apply on a monthly or bimonthly basis, since overuse can lead to brittleness.

Soak and Smear Technique for Hair

Lastly, another way to help minimize hair breakage and prevent or treat TN is to try the repurposed soak-and-smear method for hair care.

1. Shampoo and/or condition the hair normally and lightly blot hair with a towel.

2. Follow with the application of a water-based leave-in conditioner to the hair.

3. Immediately apply an oil or thick, occlusive moisturizer, such as coconut oil, olive oil, jojoba oil, petrolatum or mineral oil, to the hair.

4. Allow the hair to air dry and style as desired.

This method can be completed as often as needed throughout the week and modified depending on shampoo/conditioning needs,  the study authors note. The repurposed soak and smear is especially beneficial for patients with tightly coiled hair, as it helps reduce dryness associated with overprocessing from heat and chemical applications.

Photo Credit: Johns Hopkins Medicine

Caption: Recommendations when choosing hair products.