Dandruff, medically known as Pityriasis capitis, is a common scalp condition characterized by the visible shedding of dead skin cells. This flaking is the result of an accelerated turnover of scalp skin, which normally takes a month but happens much faster in those with the condition.
Identifying Classic Dandruff
Classic dandruff flakes are visually distinct due to their oily texture and size. These flakes are typically larger than those shed from simple dry skin, often appearing as irregular, medium-sized pieces of skin. Their color usually ranges from white to a noticeable yellowish hue, which is an indicator of their composition.
Because these flakes are shed from an oily or greasy scalp, they often look waxy or sticky. This oil content causes the skin cells to clump together, making the flakes more prominent and likely to cling to hair strands or settle on the shoulders. The flaking often appears concentrated around the crown and hairline, areas where the scalp tends to produce more oil. The underlying scalp may also show mild redness or irritation.
Distinguishing Dandruff from Dry Scalp
Dandruff and a dry scalp are two separate conditions that produce visually different types of flaking. Dandruff flakes are larger, oily, and waxy, tending to stick to the hair and scalp.
In contrast, flakes caused by a dry scalp are typically small, fine, and purely white, resembling a light dusting. These smaller flakes are dry and scatter easily, often falling off the scalp immediately. The scalp beneath dry-skin flaking usually looks matte and feels tight, lacking the greasy appearance seen with dandruff.
Dandruff often accompanies hair that is oily or greasy, as the condition involves excess oil production on the scalp. A dry scalp, however, usually results in hair that also looks and feels dry and brittle due to the lack of moisture.
When Flakes Signal Something Else
Flaking that appears more severe or is accompanied by distinct visual symptoms may signal a condition beyond common dandruff.
Seborrheic Dermatitis
Seborrheic dermatitis, considered a more intense version of dandruff, presents with thicker, larger, and noticeably greasy scales. These scales are often yellow and may form crusts that extend beyond the scalp to the ears, eyebrows, or face, differentiating it from simple dandruff.
Scalp Psoriasis
Scalp psoriasis is visually characterized by thick, well-defined plaques or patches on the scalp. These patches appear silvery-white and scaly, presenting a distinct contrast to the smaller, loose flakes of dandruff. The underlying skin is typically red and inflamed, and the thick scales adhere firmly to the scalp, making them harder to dislodge.
Tinea Capitis (Scalp Ringworm)
Tinea capitis, or scalp ringworm, is a fungal infection. Visually, this manifests as scaly, circular patches that are often accompanied by hair loss within the patch. The presence of tiny black dots, which are hairs broken off at the scalp surface, is a specific visual marker of this infection.