It is common to experience an inflammatory reaction to synthetic hair. These reactions are typically not caused by the plastic fibers themselves, such as acrylic fibers like Kanekalon and modacrylic, but by the chemicals used during manufacturing. The resulting scalp irritation is generally an inflammatory response to residues left on the surface of these fibers.
Chemical Components That Cause Sensitivity
The synthetic fibers must be treated with various chemicals to achieve their final look and texture. These surface treatments are the source of most reactions, primarily involving alkaline coatings and disperse dyes. The alkaline coating is applied to smooth the strands, prevent bacterial growth, and create a shiny finish. This residue is highly basic and can significantly disrupt the scalp’s naturally acidic pH level, which ideally sits between 4.5 and 5.5.
When the scalp sweats, moisture facilitates the leaching of this alkaline coating onto the skin, leading to immediate irritation. Disperse dyes, used to color the synthetic hair, are another major culprit. These dyes are small molecules that easily transfer from the fiber onto the skin of the scalp, neck, and face.
These chemicals are classified as irritants or allergens that become active when exposed to the heat and moisture of the scalp. While the fibers themselves are chemically stable, the surface residues are highly reactive upon contact with the skin.
Recognizing Symptoms and Reaction Types
Reactions to synthetic hair fall into two distinct dermatological categories, and understanding the difference is helpful for finding proper relief. The first type is Irritant Contact Dermatitis (ICD), which is the most common reaction and is not mediated by the immune system. ICD is characterized by an immediate burning or stinging sensation that starts shortly after installation, often caused by the alkaline coating on the hair strands. The symptoms for ICD tend to be localized to the area of contact and often present as simple redness and irritation.
The second type is Allergic Contact Dermatitis (ACD), which is a true Type IV delayed hypersensitivity reaction involving the body’s immune system. This reaction is usually triggered by the disperse dyes and requires a period of sensitization before symptoms appear. Symptoms typically become noticeable 24 to 72 hours after initial exposure to the allergen. ACD is characterized by intense itching, known as pruritus, along with more severe visible signs.
Common Symptoms
The symptoms of both reaction types can manifest as a persistent, uncomfortable itching sensation along the scalp and hairline. Redness and a visible rash are common, often presenting as small, raised bumps called papules. In more severe cases of ACD, the inflammation can lead to blistering, oozing, and the formation of weeping lesions on the scalp, neck, and sometimes the forehead. The most intense irritation often occurs where the hair extensions meet the skin, such as along the nape of the neck and the perimeter of the scalp.
Prevention and Relief Strategies
The most effective strategy for preventing a reaction to synthetic hair is to pretreat the hair before installation. This involves soaking the hair in an acidic solution to neutralize the alkaline coating and strip away unbound dyes. A simple solution is a mixture of water and apple cider vinegar (ACV), often at a ratio of one part ACV to three parts water.
The hair bundles should be soaked for 15 to 30 minutes, allowing the acidic vinegar to dissolve and remove the irritating alkaline residues. Following the soak, rinse the synthetic hair thoroughly with cool water and let it air dry completely before use. This process significantly reduces the concentration of irritants and allergens available to leach onto the scalp after installation.
For mild symptoms, several over-the-counter treatments can provide relief while the hair is worn. Topical corticosteroids, such as hydrocortisone cream, can be applied sparingly to localized areas of redness and inflammation. Oral antihistamines help manage the intense itching and discomfort associated with both ICD and ACD. Cool compresses and soothing applications like aloe vera or tea tree oil can also calm the irritated skin and reduce swelling.
If symptoms are severe, involving significant swelling, blistering, or signs of infection, consulting a doctor or dermatologist is necessary. A healthcare professional can prescribe stronger topical or oral corticosteroids, or antibiotics if a secondary infection has developed from scratching. For persistent or recurring reactions, a dermatologist may perform patch testing using samples of the synthetic hair to definitively confirm Allergic Contact Dermatitis and identify the specific chemical responsible.