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

• Acquired Pseudo-Ichthyosis
• Pityriasis Circinata
• Tinea Circinata

What is Pityriasis Rotunda? (Definition/Background Information)

• Pityriasis Rotunda is described as an uncommon skin condition that presents circular skin lesions on the chest, back, and limbs. The cause of the condition is currently not well-understood
• Two subtypes of Pityriasis Rotunda are described in the medical literature:
  • Type 1 Pityriasis Rotunda is known to develop in the background of a medical condition or a malignancy. It is often observed in older adults
  • Type 2 Pityriasis Rotunda is often associated with a positive family history. It is seen in children and young adults
• There are no well-established treatment measures available to treat Pityriasis Rotunda, although topical agents and medications may be administered. The prognosis of individuals with the condition depends upon its severity

Who gets Pityriasis Rotunda? (Age and Sex Distribution)

• Pityriasis Rotunda is a rare disorder that is mostly manifested during adulthood. However, even children may be affected
  • Type 1 Pityriasis Rotunda is common in individuals of East/Southeast Asian and South African descent. Most individuals with the type 1 subtype are older than 60 years
  • Type 2 Pityriasis Rotunda is prevalent in individuals with lighter skin tones (typically Caucasians). This type is mostly observed in individuals under 40 years of age
• Both males and females are affected, and no gender preference is noted

What are the Risk Factors for Pityriasis Rotunda? (Predisposing Factors)

The risk factors for Pityriasis Rotunda may include:

• Being of East/Southeast Asian and South African descent for type 1 Pityriasis Rotunda
• Caucasians (lighter skin-toned individuals) have a higher risk for type 2 Pityriasis Rotunda
• Type 1 Pityriasis Rotunda is also associated with the following malignancies and other conditions:
• Chronic kidney disease
• Chronic myeloid leukemia
• Heart disease
• Liver cancer
• Liver disease
• Lung disease
• Multiple myeloma
• Nutritional disease
• Squamous cell carcinoma
• Stomach cancer
• Tuberculosis

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 Pityriasis Rotunda? (Etiology)

The cause of Pityriasis Rotunda is not known at the present time.

• Type 1 Pityriasis Rotunda may be associated with malignancies, usually stomach and liver cancers, infections, and certain other conditions, such as scleroderma, and even malnutrition
• Type 2 Pityriasis Rotunda generally runs in families, and is inherited in an autosomal dominant manner

The condition is believed to be a subtype of ichthyosis vulgaris.

Autosomal dominant inheritance: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly function gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition, or pass it on to their offspring.

What are the Signs and Symptoms of Pityriasis Rotunda?

The signs and symptoms of Pityriasis Rotunda may vary between the two types (type 1 and type 2). It may also depend on the associated condition (for type 1 Pityriasis Rotunda). The signs and symptoms may include:

• Presence of numerous circular isolated skin lesions on the thighs, trunk, buttocks, legs, feet, arms, hands, and shoulders
• The color of the lesions may range from pink to brown
  • In type 1 Pityriasis Rotunda, the lesions are generally hyperpigmented and appear darker than the surrounding skin
  • In contrast, the lesions in individuals with type 2 Pityriasis Rotunda are lighter than the surrounding skin
• The lesions may be small and less than 1 cm in diameter, or large, and up to 20 cm in diameter
• In some cases, the patches can merge to form larger lesions

Once the lesions attain a certain size, they are not known to progress further (increase in size) or recede, unless the underlying causative condition is addressed.

How is Pityriasis Rotunda Diagnosed?

Pityriasis Rotunda is diagnosed on the basis of the following information:

• Physical examination of the individual and medical history evaluation
• 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, if necessary: 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
• Diagnostic tests to check for an underlying malignancy or condition if present

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 Pityriasis Rotunda?

The complications of Pityriasis Rotunda may include:

• Low self-esteem and social isolation
• Underlying malignancies can result in severe complications
• Resistance of lesions to therapy
• Decreased quality of life
• Complications may arise from the underlying conditions or malignancy, if any present

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Pityriasis Rotunda Treated?

The treatment methods for Pityriasis Rotunda may include the following:

• Topical retinoids
• Lotions containing lactic acid
• Salicylic acid ointment
• Treatment for the underlying malignancy or disorder that may be the causative factor for type 1 Pityriasis Rotunda is important

How can Pityriasis Rotunda be Prevented?

Presently, there are no methods or guidelines available for the prevention of Pityriasis Rotunda. However, the following may be considered to minimize the risk for the same:

• Individuals with type 1 disorder may benefit from seeking medical attention immediately after onset of symptoms, in order to identify the underlying condition causing Pityriasis Rotunda. This may help prevent worsening of both the pre-existing disorder and Pityriasis Rotunda
• Type 2 Pityriasis Rotunda: If there is a family history of the condition, then genetic counseling will help assess the risks, before planning for a child

Regular medical screening at periodic intervals with tests and physical examinations are recommended.

What is the Prognosis of Pityriasis Rotunda? (Outcomes/Resolutions)

The prognosis of Pityriasis Rotunda is dependent upon the severity of the signs and symptoms and associated complications, if any.

• In those with type 1 Pityriasis Rotunda, lesions are reported to resolve when the underlying condition is identified and treated. However, if the pre-existing disease is malignant, then the prognosis may be determined by the severity of the underlying malignancy
• Currently, type 2 Pityriasis Rotunda is incurable since it is a genetic disorder. However, adequate treatment may help mitigate the signs and symptoms

Additional and Relevant Useful Information for Pityriasis Rotunda:

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

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