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

• ICH (Indeterminate Cell Histiocytosis)

What is Indeterminate Cell Histiocytosis? (Definition/Background Information)

• Indeterminate Cell Histiocytosis (ICH) is a very rare skin disorder wherein an overgrowth and accumulation of certain cells, called indeterminate cells (or IC), is observed in the skin
• The indeterminate cells are a type of histiocytes (a type of inflammatory cells), similar in nature to the Langerhans cells (immune cells of the bone marrow). The term ‘histiocytosis’ is used to denote a wide group of cell proliferation disorders
• Indeterminate Cell Histiocytosis is seen in both children and adults. The condition appears as multiple skin lesions all over the body. Solitary lesions may also be noted, especially on the limbs and trunk. In most cases, these lesions are asymptomatic and no significant symptoms are present
• The cause of Indeterminate Cell Histiocytosis is generally unknown. Some researchers believe that the condition develops due to abnormalities during the migration of the indeterminate cells
• No complications are typically associated with these lesions; although rarely, the entire body may be severely affected and systemic symptoms may be present
• The treatment of Indeterminate Cell Histiocytosis may involve the use of topical creams, light therapy, and surgical excision. The prognosis is generally good with appropriate treatment. Some cases are known to spontaneously regress, while some have also displayed malignant behavior

Who gets Indeterminate Cell Histiocytosis? (Age and Sex Distribution)

• Indeterminate Cell Histiocytosis is an extremely rare condition; only around 20 cases have been reported in the medical world
• It has been seen in both children and adults
• Both male and female genders are affected
• All races and ethnic groups may be affected and no specific preference is seen

What are the Risk Factors for Indeterminate Cell Histiocytosis? (Predisposing Factors)

• Presently, there are no risk factors identified for the formation of Indeterminate Cell Histiocytosis
• Some studies indicate that ICH onset is secondary to certain triggers activated by a history of certain skin conditions (such as scabies and pityriasis rosea). In such individuals, the distribution of skin lesions matched the pattern presented by the previous skin condition

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones 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 Indeterminate Cell Histiocytosis? (Etiology)

The exact cause of Indeterminate Cell Histiocytosis is not well-understood.

• It is believed that the skin disorder may develop due to Langerhans cell abnormalities
• Some research studies inform that the disorder occurs when indeterminate cells accumulate in the skin, before they can migrate/move to the lymph nodes

The skin condition is not infectious and does not spread from one individual to another through contact.

What are the Signs and Symptoms of Indeterminate Cell Histiocytosis?

The clinical signs and symptoms of Indeterminate Cell Histiocytosis include the following:

• A random presence of multiple skin lesions (eruptions) all over the body. However, the mucosal areas, such as the oral cavity or genital mucosal membranes, are always spared
• These lesions are firm and vary from a few mm to up to 10 mm; the skin over these lesions appear unbroken
• In some cases, the lesions are solitary in nature. In such cases, it is mostly present on the arms, legs, chest, or back
• The size of solitary nodules is usually about 1 cm; they may be present with ulceration
• The skin lesions are present as nodules and papules with no signs and symptoms
• The lesions are usually red to brownish in appearance
• Multiple lesions appear in a group or collection in one area of the body, which then progressively covers the entire body
• Systemic symptoms that involve the whole body are very infrequent

In general, most individuals are of sound health status prior to the onset of the skin lesions.

How is Indeterminate Cell Histiocytosis Diagnosed?

The diagnosis of Indeterminate Cell Histiocytosis may involve the following procedures:

• The diagnosis is usually made by a complete physical examination and evaluation of medical history and family history
• Dermoscopy: Dermoscopy 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, who 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. A skin biopsy is performed to rule out other similar conditions

Note: A skin biopsy is not usually necessary, but may be performed if the healthcare provider suspects a malignancy such as a melanoma in situ of skin.

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 Indeterminate Cell Histiocytosis?

The complications of Indeterminate Cell Histiocytosis may include the following:

• The skin patches can cause emotional stress and cosmetic concerns in some individuals
• In some individuals, the signs and symptoms can be severe and systemic with extensive skin involvement
• Association with leukemia (a form of blood cancer)

How is Indeterminate Cell Histiocytosis Treated?

Due to the rarity, the treatment of Indeterminate Cell Histiocytosis is not well-established, but may include the following:

• The healthcare provider may choose to regularly observe the lesions; a “wait and watch” approach may be followed, if the lesions are observed to regress or subside
• Application of topical pure coal tar and 5-fluorouracil creams
• Phototherapy and electron beam therapy
• Electrodessication
• Chemotherapy, in some cases
• If required, a surgical excision and complete removal of the lesion
• Follow-up care with regular screening and check-ups is essential

How can Indeterminate Cell Histiocytosis be Prevented?

There is currently no effective means of prevention of Indeterminate Cell Histiocytosis, because the cause of this condition is unknown.

What is the Prognosis of Indeterminate Cell Histiocytosis? (Outcomes/Resolutions)

Based on the small number of cases, the prognosis of Indeterminate Cell Histiocytosis has been variable.

• In a majority of cases, ICH has shown a partial or complete regression. The skin lesions subside and are not known to return
• A few cases have exhibited malignant behavior and the prognosis can be adversely affected
• The association of leukemia, in some rare cases, can also worsen the outcome

Additional and Relevant Useful Information for Indeterminate Cell Histiocytosis:

• Langerhans cell histiocytosis is a rare, complicated, and non-heritable genetic disorder that can result in tumor formation in many different body parts

Please read more on Langerhans cell histiocytosis of skin by visiting the following link below:

http://www.dovemed.com/diseases-conditions/langerhans-cell-histiocytosis/