The vast majority of pimples are filled with sebum, dead skin cells, and pus, which is primarily composed of white blood cells fighting infection. However, some acne lesions appear dark red or purple, or bleed heavily when disturbed. This phenomenon occurs when intense inflammation from a deep breakout damages the surrounding tissue, specifically rupturing the tiny blood vessels that supply the skin. Understanding the depth of these lesions and the mechanism of vascular damage is key to addressing this more severe form of acne.
The Basic Structure of Acne Lesions
Acne begins within the pilosebaceous unit, which consists of a hair follicle and its attached sebaceous gland. These glands produce sebum, an oily substance that lubricates the skin. A standard pimple, or comedo, forms when sebum overproduction combines with dead skin cells to clog the follicular canal.
This blockage allows the naturally occurring bacteria, Cutibacterium acnes, to thrive. The body’s immune system initiates an inflammatory response to this bacterial overgrowth and foreign material. This localized immune activation leads to the redness and swelling characteristic of a typical surface blemish, forming the white or yellow pus seen in non-bloody lesions.
The Vascular Explanation: Why Pimple Rupture Causes Bleeding
The reason some lesions bleed is directly related to the depth of the inflammation within the skin. The skin has two main layers: the superficial epidermis and the deeper dermis, which contains an extensive network of small blood vessels, including capillaries.
When inflammation is severe, the immune response extends into the deeper dermis. This intense pressure and tissue damage cause the wall of the blocked follicular unit to rupture, spilling sebum, bacteria, and debris into the surrounding dermal tissue. This rupture often extends to the nearby capillaries, which are fragile and easily broken.
The resulting internal bleeding means blood immediately mixes with the pus and debris inside the cavity. If the capillary damage is significant, the lesion may become entirely filled with blood or bleed profusely when the surface is broken. Trauma, such as picking or squeezing, drastically increases the likelihood of rupturing these vessels, forcing blood into the lesion and exacerbating the problem.
Types of Deep Lesions Prone to Hemorrhage
The acne lesions most likely to involve significant bleeding are inflammatory nodules and cysts, which start deep within the dermis. Inflammatory nodules form when the follicular wall ruptures beneath the skin’s surface, triggering a widespread, painful inflammatory reaction. These lesions feel like firm, solid lumps because the damage occurs in the lower layers of the skin.
Acne cysts are a more severe form, characterized by large, painful, pus-filled lumps that extend into the dermal and subdermal layers. Since both nodules and cysts originate at this depth, they are far more likely to rupture surrounding blood vessels than smaller papules or pustules. The blood filling these deep lesions contributes to their dark red or purplish appearance and indicates potential tissue destruction. Bleeding can also be caused by excoriated acne, which is external trauma from persistent picking or scratching, regardless of the lesion’s initial depth.
Safe Management of Bleeding Pimples and Scar Prevention
The most important step in managing a bleeding lesion is to stop all manipulation, as picking or squeezing increases tissue trauma and the risk of permanent marks. Once bleeding occurs, the area should be gently cleaned with mild soap and water to prevent secondary infection. Applying light, sustained pressure with a clean cloth or gauze will help stop the flow of blood from the ruptured capillaries.
The deep inflammation and vascular damage that cause bleeding increase the risk of scarring. This tissue destruction can lead to depressed scars, such as icepick or boxcar scars, or dark discoloration known as post-inflammatory hyperpigmentation. Allowing the lesion to heal undisturbed and keeping the area protected minimizes the risk of these lasting consequences. If a deep lesion is painful, shows signs of spreading infection, or bleeds uncontrollably, consult a dermatologist for professional drainage or targeted medical treatment.