Introduction Demographics Causes Clinical features Diagnosis Differential diagnoses Treatment Outcome
Lipoid proteinosis is a rare genetic skin disease in which an amorphous hyaline material is deposited in the skin, mucosa, and internal organs [1,2]. It often presents as hoarseness in early childhood, associated with thickening of skin and mucosae [3].
It is also called hyalinosis cutis et mucosae, and Urbach-Wiethe disease.
Lipoid proteinosis is inherited as an autosomal recessive disorder. This means that both parents of an affected individual carry an abnormal gene. The parents are often related to each other by birth, and there may be a family history of the disease.
Lipoid proteinosis affects males and females equally.
Lipoid proteinosis is due to loss of function mutations in a gene encoding extracellular matrix protein 1 (ECM1) on band 1q21. This encodes an important structural protein in the basement membrane and extracellular matrix [6,7].
Lipoid proteinosis often presents in early childhood, but may rarely present at birth or in adulthood if cutaneous manifestations are subtle [1,2].
It has variable phenotype, ie, clinical features differ between affected individuals, even within families. Although skin and mucous membranes of mouth, pharynx, and larynx are commonly affected, hyaline material may infiltrate any part of the body [7].
The characteristic skin changes of lipoid proteinosis tend to occur in overlapping stages [1,3]. They are due to dermal infiltration with hyaline.
Other common cutaneous features include:
Hyaline infiltration of the respiratory tract can lead to:
Lipoid proteinosis may affect the nervous system. Features may include:
When lipoid proteinosis affects the eye, it can lead to:
The 2 most reliable signs of lipoid proteinosis are [3]:
Further testing should be performed in patients with suggestive clinical features.
Depending on clinical presentation, other diagnoses to consider may include [2,3,9]:
There is no known effective treatment for lipoid proteinosis. The following have been trialed with variable success [2,3,10].
There may be potential for development of effective treatments for lipoid proteinosis in the future, such as recombinant ECM1 gene therapy [10].
Patients with lipoid proteinosis are often under the care of multiple specialists, including:
Lipoid proteinosis is a chronic disease with a generally favourable prognosis that runs a slowly progressive, benign course [1,2,11]. Lifespan is normal for most patients, with the exception of those with central nervous system and/or respiratory tract involvement [1].
However, progressive thickening of the skin and scarring, along with abnormal voice, can have a significant psychosocial impact, leading to difficulties at work, low self-esteem and overall poor quality of life [3].
