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

• APPM (Acral Persistent Papular Mucinosis)

What is Acral Persistent Papular Mucinosis? (Definition/Background Information)

• Acral Persistent Papular Mucinosis (APPM) is the localized form of lichen myxedematosus, which is a rare skin abnormality characterised by mucin deposition in the skin
• Acral Persistent Papular Mucinosis is an uncommon skin condition that presents tiny, firm, skin-colored papules on some parts of the body, particularly on the back of the hands and wrists
• The exact cause of development of Acral Persistent Papular Mucinosis is currently unknown. It may be due to a local  abnormality of the immune system
• The condition is usually diagnosed by a skin biopsy. Following its diagnosis, if necessary, a treatment of the condition is undertaken. However, in many cases, Acral Persistent Papular Mucinosis is a self-resolving skin condition
• The treatment measures may include light therapy, use of topical creams, dermabrasion, and intralesional injections. The prognosis of Acral Persistent Papular Mucinosis is usually good in a majority, since only skin manifestations are observed

Who gets Acral Persistent Papular Mucinosis? (Age and Sex Distribution)

• Acral Persistent Papular Mucinosis is a rare skin condition that is usually diagnosed in young and middle-aged adults (usually around the 40s)
• Both males and females are affected
• All racial and ethnic groups are affected and no predilection is reported

What are the Risk Factors for Acral Persistent Papular Mucinosis? (Predisposing Factors)

• Specific risk factors for Acral Persistent Papular Mucinosis are presently unknown
• A family history of the condition is rarely noted
• Some localized forms of lichen myxedematosus are associated with exposure to toxic substances, such as certain oils, and contaminated L-tryptophan (an amino acid)

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 Acral Persistent Papular Mucinosis? (Etiology)

• The exact cause of Acral Persistent Papular Mucinosis (APPM) formation is generally unknown. It may be due to a local abnormality of immune function that typically involves the skin (not a systemic condition)
• Some familial forms of APPM have been reported indicating a genetic cause
• It is a non-contagious condition that cannot spread from one individual to another. This means that one cannot get APPM through direct contact or from being in close proximity to an individual having the condition

What are the Signs and Symptoms of Acral Persistent Papular Mucinosis?

The signs and symptoms of Acral Persistent Papular Mucinosis may include:

• Presence of numerous, small papules on skin that are between 2-5 mm in size
• The skin lesions are firm and flesh-colored
• A papule is an area of abnormal skin tissue that is less than 1 centimeter around. Usually a papule has distinct borders, and it can appear in a variety of shapes
• The papules can be present anywhere on the body, but are mostly noted on the back of the hands and wrists, and distal forearms
• The presentation of the skin lesions are observed symmetrically on the body
• Thickening of skin may be observed

How is Acral Persistent Papular Mucinosis Diagnosed?

Acral Persistent Papular Mucinosis may be diagnosed through the following tools:

• Complete physical examination with evaluation of medical history
• 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
• A differential diagnosis may be undertaken to exclude scleromyxedema (that presents systemic symptoms) and other localized forms of papular mucinosis

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 Acral Persistent Papular Mucinosis?

The complications of Acral Persistent Papular Mucinosis may include:

• Scratching or itching of the lesions may lead to bleeding and ulceration. This can cause secondary bacterial or fungal infections to develop
• Emotional stress due to cosmetic concerns

How is Acral Persistent Papular Mucinosis Treated?

Acral Persistent Papular Mucinosis is difficult to treat, but can resolve spontaneously on its own, like all localized cutaneous forms of papular mucinosis. In case the condition does not get better, then the following treatment options may be considered:

• Use of topical steroids and topical or oral retinoids
• Psoralen and ultraviolet A (PUVA) therapy
• Dermabrasion
• CO2 laser therapy
• Intralesional steroid injections and intralesional hyaluronidase injections
• Newer treatment methods, such as topical tacrolimus creams, have been shown to be successful in some cases
• Symptomatic and supportive therapy, if needed

How can Acral Persistent Papular Mucinosis be Prevented?

Current medical research has not established a method of preventing the occurrence of Acral Persistent Papular Mucinosis.

What is the Prognosis of Acral Persistent Papular Mucinosis? (Outcomes/Resolutions)

• The prognosis of Acral Persistent Papular Mucinosis is generally good with adequate treatment
• Also, in many cases, the condition is known to be self-limiting and it gets better on its own without the need for any treatment

Additional and Relevant Useful Information for Acral Persistent Papular Mucinosis:

• Do not pick or scratch the skin lesions
• 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