Epidermoid Cysts

Little, noncancerous pimples beneath the skin are called epidermoid cysts. While they can occur anywhere on the skin, the face, neck, and trunk exhibit them the most frequently.

Epidermoid cysts seldom create issues or require treatment because of their gradual growth and frequent lack of discomfort. If a cyst concerns you due to its appearance or if it is painful, burst, or infectious, you may decide to have a doctor remove it.

While they are distinct, epidermoid cysts are frequently confused with sebaceous cysts. Less frequently occur true sebaceous cysts. They come from the glands that release the lubricating oil that keeps hair and skin smooth (sebaceous glands).

Epidermoid Cysts: Causes

Your body constantly loses the thin, protective layer of cells that make up the epidermis, the top layer of your skin. The majority of epidermoid cysts develop when these cells proliferate rather than slough off when they travel deeper into your skin. Cysts can occasionally develop as a result of skin damage or irritation to the outermost layer of a hair follicle.

The cyst's walls are created by epidermal cells, which subsequently release the protein keratin into the cavity. The thick, yellow fluid that occasionally flows from the cyst is keratin. A damaged skin oil gland or hair follicle may be the cause of this aberrant cell development. Although they are distinct, epidermoid cysts are frequently confused with sebaceous cysts. Less frequently occur true sebaceous cysts. They come from the glands that release the lubricating oil that keeps hair and skin smooth (sebaceous glands).

The follicular infundibulum is the source of epidermoid cysts. These cysts often develop as a result of the follicular orifice becoming blocked. Via a hole filled with keratin, the cyst interacts with the skin's surface. Considering that people with acne vulgaris may have several epidermoid cysts emerging from comedones, disruption of the follicle is crucial in the pathophysiology. They can also be brought on by trauma and penetration injuries that result in epithelial implantation.

The stratified squamous epithelium that lines epidermoid cysts causes a build-up of keratin in the dermis or subepidermal layer. The cysts usually don't cause any symptoms until they explode. As cysts burst, soft, yellow keratin is forced into the dermis and surrounding tissue, triggering an inflammatory response. Human papillomavirus (HPV) infection and ultraviolet (UV) light have recently been linked to the development of epidermoid cysts.

The cyst is lined with stratified squamous epithelium. The dermis has an epithelial-lined cyst that is filled with laminated keratin, according to histological analysis. The cyst's lining resembles the surface epithelium but differs in that it is devoid of rete ridges. Keratohyalin granules are distributed across a granular layer.

Epidermoid Cysts: Symptoms

Physical examination often reveals a non-fluctuant, compressible mass that ranges in size from 0.5 cm to several centimeters. Punctums, the center aperture of comedones, are frequently mentioned. Usually asymptomatic, epidermoid cysts can closely mimic a furuncle in terms of pain to probing, redness, and swelling if they burst. It's possible to describe a bad-smelling, cheese-like substance that discharges from the skin.

Other patients could mention an incident when they fell on their back or had their back slapped, which resulted in severe swelling and a cystic rupture. The face, neck, chest, upper back, scrotum, and genitalia are the most typical locations for epidermoid cysts, and they can occur anywhere. If there has been a penetrating injury, they can also appear on the palms, plantar side of the feet, and buttocks.

The nail plate may alter if it happens on the distal end of the fingers. Finding out if the cyst is a singular instance, brought on by medicine, or a result of a hereditary condition might be aided by taking a thorough medical history.

The following are possible side effects of epidermoid cysts −

  • Inflammation. Even if an epidermoid cyst is not infectious, it may become sensitive and swollen. Removing an inflammatory cyst is challenging. Your doctor will probably wait to remove it till the irritation goes down.

  • Rupture. A boil-like illness caused by a burst cyst frequently needs rapid medical attention.

  • Infection. Infected and uncomfortable cysts are possible (abscessed).

  • A skin cancer. Epidermoid cysts can, in extremely rare circumstances, cause skin cancer.

Epidermoid Cysts: Risk Factors

Several factors play an important role in the development of epidermoid cysts which includes −

  • Being of a certain age

  • Having specific uncommon genetic diseases

  • Causing skin damage

Epidermoid Cysts: Diagnosis

The diagnosis of epidermoid cysts is mainly done based on history and some of the tests may be required for confirmation and to rule out underlying causes

Usually, a cyst examination by a doctor will reveal the condition. Your doctor may also scrape out a piece of skin to inspect it under a microscope or take a biopsy of it to send to the lab for further examination.

While epidermoid cysts resemble sebaceous cysts, they are not the same. Damage to the outer layer of skin or the hair follicles causes true epidermoid cysts (epidermis).

Epidermoid Cysts: Treatment

The treatment is based on the severity of the symptoms. Your doctor may advise conservative or surgical treatment.

The cyst must be completely surgically removed while leaving the cyst wall in place for the best results. If an infection is current, total excision should be postponed since it will be challenging to dissect the planes. In these circumstances, a first incision and drainage may be advised due to the possibility of a future recurrence.

To reduce bleeding, a topical anesthetic with epinephrine is suggested. Avoid injecting the anesthetic directly into the cyst; instead, administer it around the cyst. It is possible to use a small diameter elliptical incision with the center core, or punctum. Maintaining the incision in the smallest skin tension lines is crucial for achieving the best aesthetic effects.

The best results will come from a multi-layered subcuticular and epidermal closure. A punch biopsy and evacuation of the intact cyst through the little defect or a conventional excision are two other surgical options. In addition to delaying surgical removal, if there is surrounding inflammation, intralesional triamcinolone may be utilized to assist reduce inflammation. Cysts do not recur after they have burst and had their lining removed. The whole cystic lining must be removed, nevertheless, to reduce recurrence.

Epidermoid Cysts: Prevention

Epidermoid cysts cannot be prevented, as far as is known. But if you don't press, pop, poke a needle in it, or cut it open, you may avoid infection and scars. This frequently results in scarring and infection. You should get medical attention if it becomes very infected or inflamed.


The primary care physician, dermatologist, nurse practitioner, surgeon, and internist frequently deal with epidermal cysts. Even though the majority of these cysts are benign, it's crucial to send the removed sample for testing to be sure it's not cancerous.

The results are great when entirely removed. Recurrences, however, are frequent in people with hereditary disorders.

Dr. Durgesh Kumar Sinha
Dr. Durgesh Kumar Sinha


Updated on: 26-Apr-2023


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