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

• APEC (Asymmetric Periflexural Exanthem of Childhood)
• Superimposed Lateralised Exanthem of Childhood
• Unilateral Laterothoracic Exanthem (ULE)

What is Asymmetric Periflexural Exanthem of Childhood? (Definition/Background Information)

• Asymmetric Periflexural Exanthem of Childhood (APEC) is an uncommon skin condition that is observed in young children. It manifests in the form of tiny pink-red rashes that start from one armpit and spreads to the chest and back. These may be itchy, and the child may present other symptoms such as fever and sore throat
• The cause of the condition is not well understood, but some experts believe that it may be due a viral infection. Asymmetric Periflexural Exanthem of Childhood is a self-limited condition and no treatment is generally necessary; APEC typically resolves by its own within about 4-6 weeks

Who gets Asymmetric Periflexural Exanthem of Childhood? (Age and Sex Distribution)

• Asymmetric Periflexural Exanthem of Childhood (APEC) is mainly observed in infants and young children between the ages of 6 months and 5 years (mean age 2 years). It is uncommon outside this age group and is extremely rare in adults
• Both male and female genders are affected, although a female predominance is observed (female-male ratio is 2:1)
• Individuals of all racial and ethnic groups may be affected. However, a vast majority of cases are reported among Caucasian children
• A higher incidence of APEC is reported from France and Italy

What are the Risk Factors for Asymmetric Periflexural Exanthem of Childhood? (Predisposing Factors)

No risk factors have been clearly identified for Asymmetric Periflexural Exanthem of Childhood (APEC).

• APEC is frequently observed in very young children
• Caucasians may have a higher risk for the condition, since a large subset of cases are observed in them
• APEC is more common during spring and winter
• Infection by certain viruses may be a risk factor, but this is currently unproven

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 Asymmetric Periflexural Exanthem of Childhood? (Etiology)

• The exact cause of formation of Asymmetric Periflexural Exanthem of Childhood is not well-established
• Viral infections, such as by adenovirus, Epstein-Barr virus, parainfluenza virus, and parvovirus B19, are implicated as being causative, but currently remain unsubstantiated

The condition is not known to spread from one individual to another through physical contact or sharing of items.

What are the Signs and Symptoms of Asymmetric Periflexural Exanthem of Childhood?

The signs and symptoms of Asymmetric Periflexural Exanthem of Childhood may include the following:

• Onset of skin eruptions in the form of pink or red rashes mostly from one of the armpits; hence, it is also referred to as Unilateral Laterothoracic Exanthem
• The rashes spread down the body side and inner arm; in some cases, both sides of the body may be covered in rashes (bilateral manifestation)
• In some cases, the onset of the skin rashes may be from the groin region
• The affected regions may include the genitals, feet, hands, and face
• The rashes may consist of papules (raised bumps) and macules (flat and wide discolored area)
• The size of the individual lesions may vary from 1 to 4 mm; these may be initially discrete, but can combine to form larger skin patches
• Sometimes, tiny blood spots/blisters may be noted
• Nearly half of the children (about 50%) may present itching and regional (armpit and groin) lymph node enlargement
• Over a few weeks, the lesions may become flat and scaly; older lesions may turn grayish

Some children may present other signs and symptoms of a viral illness such as fever, sore throat, and runny nose. This may be sometimes accompanied by vomiting or diarrhea.

How is Asymmetric Periflexural Exanthem of Childhood Diagnosed?

A diagnosis of Asymmetric Periflexural Exanthem of Childhood can be challenging; in many cases, it may be initially misdiagnosed. The diagnosis may involve the following tests and procedures:

• Physical examination and a complete medical history; a dermatologist will carefully examine the lesions to help in the diagnosis
• Dermoscopy: Dermoscopy is a diagnostic tool where a dermatologist examines the skin using a special magnified lens
• Blood tests, to rule out other causes such as infections
• Potassium hydroxide (KOH) test: The KOH prep involves microscopic observation of skin scrapings for structures belonging to fungi
• 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 biopsy of the lesion is usually performed to confirm the diagnosis. A 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 skin tissue biopsy is generally not necessary but may be performed to rule out other conditions or infections.

A differential diagnosis to eliminate other conditions/infections may be considered, before arriving at a definitive diagnosis. These may include:

• Atypical pityriasis rosea
• Drug-related eruptions
• Eczema
• Miliaria
• Ringworm (fungal) infection
• Scabies
• Viral exanthems

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 Asymmetric Periflexural Exanthem of Childhood?

Significant complications of Asymmetric Periflexural Exanthem of Childhood are generally not observed. However, sometimes the following may occur:

• Children may have emotional and psychological stress due to constant scratching of the rashes
• Cosmetic issues

How is Asymmetric Periflexural Exanthem of Childhood Treated?

Generally, there is no treatment required for Asymmetric Periflexural Exanthem of Childhood. In a vast majority of children, the condition resolves by its own without any treatment.

• If necessary, topical creams and applications may be recommended to reduce itching and discomfort
• Oral antihistamines may be administered, based on the healthcare provider’s advice

How can Asymmetric Periflexural Exanthem of Childhood be Prevented?

Currently, there are no available guidelines or measures to prevent Asymmetric Periflexural Exanthem of Childhood.

• However, maintaining hygiene, keeping the skin moisturized, and avoiding the tendency to itch, can help control the symptoms and prevent from worsening of the skin texture
• Clipping the nails short, especially in children, can be beneficial; it may keep them from scratching the lesions

What is the Prognosis of Asymmetric Periflexural Exanthem of Childhood? (Outcomes/Resolutions)

• The prognosis of Asymmetric Periflexural Exanthem of Childhood is generally excellent since it is a self-limited condition
• Most of the cases resolve within about 4 to 6 weeks. Even though some may rarely take 12 weeks to resolve, the prognosis is usually excellent

Additional and Relevant Useful Information for Asymmetric Periflexural Exanthem of Childhood:

Presently, there is no evidence to prove that dietary factors have an influence on Asymmetric Periflexural Exanthem of Childhood.