At first glance, the image looks almost unreal: a person’s forehead is covered with dozens of dark, raised spots while a dermatologist carefully examines and removes material from the affected area.

Although the appearance may be shocking, clusters of dark plugs on the skin can have several possible explanations. In many cases, these spots are related to blocked pores, accumulated keratin, sebum, or other material trapped inside hair follicles. However, the exact cause cannot be confirmed from a photograph alone.

What Are the Dark Plugs?

The dark material visible in the image resembles keratin and sebum plugs, similar in appearance to open comedones (blackheads). When a pore becomes blocked with oil and dead skin cells, the material inside can become exposed to air and appear dark.

Importantly, the dark color does not necessarily mean dirt. The color of an open comedone is largely associated with oxidation of the material at the surface.

In some unusual cases, numerous plugs can develop in a concentrated area because of an underlying skin condition.

Why Can So Many Appear in One Area?

There are several possible reasons for extensive pore blockage, including:

• Excess oil production
• Accumulation of dead skin cells
• Abnormal follicular keratinization
• Certain inherited or localized skin conditions
• Chronic inflammation around hair follicles
• Hormonal influences
• Occlusive skincare or cosmetic products

One possibility dermatologists may consider when numerous comedone-like openings occur in a localized pattern is nevus comedonicus, a relatively uncommon follicular condition. It typically produces groups of enlarged, plugged follicles and can sometimes become inflamed.

However, a photograph alone is not enough to diagnose nevus comedonicus or any other specific condition.