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

• CPH (Circumscribed Palmar Hypokeratosis)

What is Circumscribed Palmar Hypokeratosis? (Definition/Background Information)

• Circumscribed Palmar Hypokeratosis (CPH) is an uncommon and recently described entity that is characterized as a round-to-oval-shaped red lesion on the palms with well-defined borders. It is mainly observed in middle-aged and older women
• The cause of Circumscribed Palmar Hypokeratosis is presently unknown. CPH may be misdiagnosed as Bowen disease or palmar porokeratosis. The skin condition may persist for several years, but is not observed to present any significant complications

Who gets Circumscribed Palmar Hypokeratosis? (Age and Sex Distribution)

• Circumscribed Palmar Hypokeratosis is typically observed in women in the 40-70 years’ age group. A solitary case of congenital CPH has been recorded
• Worldwide, there is no racial or ethnic preference observed. However, the condition is extremely rare and only about 50 cases have been recorded in the medical history

What are the Risk Factors for Circumscribed Palmar Hypokeratosis? (Predisposing Factors)

• Presently, the risk factors for Circumscribed Palmar Hypokeratosis are not yet identified

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 Circumscribed Palmar Hypokeratosis? (Etiology)

The exact cause of formation of Circumscribed Palmar Hypokeratosis is unknown. Some of the causes attributed to the condition by experts include:

• Abnormal loss of stratum corneum, the topmost layer of skin
• Abnormal keratinization
• Infection by human papillomavirus (HPV)
• Trauma to the region

The condition is not contagious, and it does not spread from one individual to another.

What are the Signs and Symptoms of Circumscribed Palmar Hypokeratosis?

The signs and symptoms of Circumscribed Palmar Hypokeratosis may include:

• Presence of a solitary red circular-to-oval rash on the palms; multiple lesions are rare
• The center of the smooth lesion typically presents thin skin, which may be scaly
• Many of the lesions are found at the base of the thumb or little finger
• The back of the hand may be rarely affected
• If the sole of the foot is affected, the condition is termed Circumscribed Plantar Hypokeratosis
• Occasionally, multiple lesions may be observed on the palms and soles
• The lesions are well-circumscribed, meaning they are present with clear boundaries

No pain, itching, or irritation is generally reported. The size of the lesion does not increase, and it remains stable.

How is Circumscribed Palmar Hypokeratosis Diagnosed?

A diagnosis of Circumscribed Palmar Hypokeratosis may involve the following exams and procedures:

• Physical examination of the individual and medical history evaluation; a visual exam may help the healthcare expert suspect the condition, especially if it is longstanding and no progression is seen
• Blood tests and culture studies, as needed
• 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 tissue 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

A differential diagnosis may be necessary to eliminate other conditions that present similar signs and symptoms such as:

• Bowen disease (squamous cell carcinoma type)
• Palmar porokeratosis

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 Circumscribed Palmar Hypokeratosis?

The possible complications due to Circumscribed Palmar Hypokeratosis include:

• Emotional stress due to cosmetic issues
• Longstanding lesion
• Treatment complications including resistance to treatment

The condition is not known to undergo any malignant transformations.

How is Circumscribed Palmar Hypokeratosis Treated?

Treatment measures for Circumscribed Palmar Hypokeratosis are not well-defined. In many individuals, no treatment may be necessary; however, this is based on the healthcare provider’s evaluation.

When necessary, the healthcare provider may consider the following measures:

• Application of topical creams such as calcipotriol or 5-fluorouracil
• Topical corticosteroids are not effective
• Cryotherapy
• Photodynamic therapy

Regular follow up visits with the healthcare provider is important and recommended.

How can Circumscribed Palmar Hypokeratosis be Prevented?

Presently, there are no preventative measures available for Circumscribed Palmar Hypokeratosis since the cause of the condition is unknown.

What is the Prognosis of Circumscribed Palmar Hypokeratosis? (Outcomes/Resolutions)

• The prognosis of Circumscribed Palmar Hypokeratosis is generally good because it is a benign condition, although the lesion may persist for decades
• In some cases, with adequate and regular treatment (topical applications), the condition is known to recede and disappear in about 4-5 years

Additional and Relevant Useful Information for Circumscribed Palmar Hypokeratosis:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/healthy-living/skin-disorders/