What are the other Names for this Condition? (Also known as/Synonyms)

• Traumatic EIC (Traumatic Epidermal Inclusion Cyst)
• Traumatic Epidermoid Cyst

What is Traumatic Epidermal Inclusion Cyst? (Definition/Background Information)

• Traumatic Epidermal Inclusion Cyst (Traumatic EIC) is a benign skin cyst that is usually caused by trauma or injury to the skin
• Any individual of any age is prone to this condition. Traumatic Epidermal Inclusion Cysts are generally observed at the site of injury, usually on the palms and soles
• Some health conditions, trauma due to a crushing injury, body-piercing, or a minor surgery can be risk factors for Traumatic Epidermal Inclusion Cysts that occur secondary to the trauma
• In a majority of cases, no treatment may be necessary, unless it causes discomfort in the individual including cosmetic issues
• A simple surgical excision of Traumatic Epidermal Inclusion Cyst is considered curative, and the prognosis is excellent with suitable treatment

Who gets Traumatic Epidermal Inclusion Cyst? (Age and Sex Distribution)

• Traumatic Epidermal Inclusion Cyst is a benign cyst that can affect any individual of any age, though they are commonly observed during middle-age (in the 3^rd and 4^th decade)
• Both males and females may be affected, but males are affected more than females (male-female ratio is 2:1)
• Individuals of all racial and ethnic background may be affected. Worldwide, no geographical localization has been reported

What are the Risk Factors for Traumatic Epidermal Inclusion Cyst? (Predisposing Factors)

The risk factors for Traumatic Epidermal Inclusion Cyst include the following:

• Any crushing or blunt injury; scratch injury
• Minor surgical procedures, in some cases
• Body-piercing
• Footwear injury such as from wearing high-heeled shoes

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Traumatic Epidermal Inclusion Cyst? (Etiology)

Traumatic Epidermal Inclusion Cyst occurs against a backdrop of trauma that affects the skin.

• When trauma occurs, the skin surface (epidermis) gets into the deeper skin (dermis) causing the formation of a cyst, which is a fluid-containing membranous sac
• The cyst typically forms at the site of the skin injury

What are the Signs and Symptoms of Traumatic Epidermal Inclusion Cyst?

Most Traumatic Epidermal Inclusion Cysts are asymptomatic. In some, the signs and symptoms observed may include:

• It usually occurs as a single cyst on the skin. It can range in size from a few millimeters to a centimeter (size can range from 5 mm to 5 cm)
• The skin over the nodules may have a reddish discoloration and may be raised (inflamed)
• These cysts are usually painless and non-itchy. They are mostly well-demarcated and firm to touch
• Traumatic Epidermal Inclusion Cysts can occur at any location on the body, at the site of the trauma. The most common sites include the palms of the hand and soles of the feet; other sites include the fingertips and oral cavity (mouth)
• Large inflamed EICs may present pain; on the hands or feet can limit the range of motion and interfere with one’s work 

EIC typically occurs as a single cyst that grows slowly. However, multiple cysts may also be seen.

How is Traumatic Epidermal Inclusion Cyst Diagnosed?

A diagnosis of Traumatic Epidermal Inclusion Cyst may involve the following:

• A thorough physical examination and medical history evaluation
• Dermoscopy: It is a diagnostic tool where a dermatologist examines the skin using a special magnified lens
• Wood’s lamp examination: In this procedure, the healthcare provider examines the skin using ultraviolet light. It is performed to examine the change in skin pigmentation
• Skin biopsy: A skin biopsy is performed and sent to a laboratory for a pathological examination. The pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis

Note: A biopsy is not usually necessary but may be performed to rule out other skin conditions with similar signs and symptoms.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Traumatic Epidermal Inclusion Cyst?

Traumatic Epidermal Inclusion Cysts are benign cysts that do not cause any significant complications. However, the following factors may be a cause for concern:

• The presence of large-sized cysts may result in cosmetic issues
• Superimposed bacterial or fungal infection may develop at the lesion site
• Localized cellulitis
• Sometimes, they can rupture, become infected and release pus. When these heal, they can leave a scar behind
• Complications may arise from treatment
• Recurrence of the cyst after treatment

How is Traumatic Epidermal Inclusion Cyst Treated?

The treatment of Traumatic Epidermal Inclusion Cyst may involve the following:

• In a majority of cases, removal of the cyst is not necessary unless it causes bothersome signs and symptoms and cosmetic issues
• Intralesional injections may be considered for inflamed cysts based on the healthcare expert’s evaluation. This can help prevent infection and avoid surgical incision and drainage of the cyst
• The definitive treatment is a complete surgical excision, which can result in a cure
• Treating any superimposed infections
• The treatment may also involve treating the underlying injury or health condition

How can Traumatic Epidermal Inclusion Cyst be Prevented?

• Currently, there are no known methods available to prevent the occurrence of Traumatic Epidermal Inclusion Cysts
• However, prompt treatment of any skin trauma may help lower the risk for cyst formation

What is the Prognosis of Traumatic Epidermal Inclusion Cyst? (Outcomes/Resolutions)

The prognosis for Traumatic Epidermal Inclusion Cyst is excellent with appropriate treatment since it is a benign cyst. However, EICs are generally known to recur.

Additional and Relevant Useful Information for Traumatic Epidermal Inclusion Cyst:

• There is no evidence to prove that oily foods and chocolate-based products have an influence on the development of Traumatic Epidermal Inclusion Cyst
• Cleaning the skin too hard with strong chemicals or soaps may aggravate the skin condition. Care must be taken avoid strong soaps and chemicals that could potentially worsen the condition

The presence of dirt on the body is not a causative factor for the condition. However, it helps to be clean and hygienic, which may help the condition from getting worse