Eczema, a common inflammatory skin condition also known as dermatitis, affects many people, manifesting as rashes, dryness, and intense itching. When this condition occurs on the scalp, it is often categorized as either atopic dermatitis or seborrheic dermatitis. The inflammation and irritation associated with scalp eczema negatively impact the integrity of the hair growth cycle. The resulting scalp environment can contribute to noticeable hair thinning or shedding. This hair issue stems from two primary mechanisms: the biological stress of inflammation on the hair follicle and the physical trauma caused by responding to the intense itch.
Scalp Inflammation and Follicle Damage
The primary mechanism of hair loss in scalp eczema involves a chronic inflammatory cascade that disrupts the normal function of hair follicles. Dermatitis causes an immune response in the skin, characterized by redness, scaling, and irritation. This hostile environment weakens the hair roots and prematurely signals the hair to transition from its active growth phase (anagen) into the resting and shedding phases.
In seborrheic dermatitis, the condition is often linked to an overproduction of sebum, the scalp’s natural oil. This excess sebum can lead to an overgrowth of the naturally occurring yeast Malassezia. The presence of this yeast triggers further irritation and inflammation around the follicle.
Chronic inflammation associated with eczema can restrict blood flow to the hair roots, depriving them of necessary oxygen and nutrients. This often pushes hair follicles into the shedding phase, resulting in temporary hair loss known as telogen effluvium. Additionally, the thick scales and plaques that form on the scalp can physically clog the follicle openings, making it difficult for new hairs to emerge and causing existing hairs to shed more easily.
Physical Trauma and Hair Breakage
A secondary and often more visible cause of hair loss is the mechanical damage inflicted by the patient. The intense, persistent itching (pruritus) that characterizes scalp eczema compels frequent and aggressive scratching or rubbing. This physical manipulation directly traumatizes the hair shaft and the surrounding scalp tissue.
The repetitive friction can cause the hair shaft to break off, a condition known as trichorrhexis nodosa. This disorder is characterized by weak spots or nodules along the hair fiber, which fracture easily at the site of trauma. This results in hair loss that presents as uneven, broken strands rather than hair falling out from the root.
Aggressive scratching can also cause breaks in the skin barrier, leading to open sores and potential secondary bacterial or fungal infections. These infections introduce another layer of inflammation, which further damages the hair follicle and exacerbates shedding. Treating the infection is required along with managing the underlying eczema to halt the hair loss.
Differentiating Eczema-Related Hair Loss
It is important to determine whether hair loss is a direct result of eczema or another dermatological condition, as the treatment approach will vary. Eczema-related hair loss is typically temporary and non-scarring, meaning the hair follicle structure remains intact and capable of regrowth. This type of shedding often appears as diffuse thinning across the affected areas of the scalp or as patches of broken hair shafts.
Other conditions present differently; for example, alopecia areata causes distinct, smooth, circular patches of complete hair loss without the associated redness, scaling, or itchiness of eczema. Scalp psoriasis, while also inflammatory, usually presents with thicker, more well-defined silvery scales. Consulting a dermatologist is necessary to receive an accurate diagnosis. They can visually inspect the scalp and rule out fungal infections like tinea capitis, which also cause scaly patches and hair loss.
Management and Regrowth Strategies
Controlling the underlying scalp inflammation is the most effective way to stop eczema-related hair loss and promote regrowth. Treatment often begins with medicated shampoos that contain ingredients such as ketoconazole, selenium sulfide, or zinc pyrithione. These ingredients help manage the yeast and scaling associated with seborrheic dermatitis. These agents normalize the scalp environment, reducing the inflammatory signal to the hair follicles.
For more significant inflammation, a dermatologist may prescribe topical anti-inflammatory treatments, such as corticosteroids or calcineurin inhibitors, to reduce redness and irritation. Minimizing physical trauma is also paramount. This can be achieved by using cool compresses to alleviate intense itching and keeping fingernails trimmed short to reduce the mechanical damage caused by scratching.
Once the eczema is successfully managed, the hair growth cycle typically rebalances. New hair growth is generally observed within a few months of effective treatment. Gentle hair care practices, including avoiding harsh chemical treatments and excessive heat styling, support the healing process and minimize trauma to the newly emerging hair.