Cutis laxa may be inherited or acquired. There are 4 hereditary forms:
The autosomal recessive forms tend to be more common, and one of them causes potentially lethal cardiovascular, respiratory, and gastrointestinal complications. The other inherited forms may be relatively benign.
Rarely, infants can acquire cutis laxa after a febrile illness or after exposure to a specific drug (eg, hypersensitivity reaction to penicillin, fetal exposure to penicillamine). In children or adolescents, cutis laxa usually develops after a severe illness involving fever, polyserositis, or erythema multiforme. In adults, it may develop insidiously or in association with a variety of disorders, particularly plasma cell dyscrasias. The underlying defect in these acquired cases is unknown, but fragmented elastin is present in all forms.
Cutis laxa is caused by abnormal elastin metabolism that results in reduced elasticity of the skin. The precise cause is unknown except in congenital cases where an underlying gene defect (eg, in the ELN, FBLN4, FBLN5, ATP6V0A2, or ATP7A genes) can be identified. Several factors, such as copper deficiency, elastin quantity and morphology, and elastases and elastase inhibitors, are implicated in the abnormal elastin degradation.
In hereditary forms, dermal laxity may be present at birth or develop later; it occurs wherever the skin is normally loose and hanging in folds, most obviously on the face. Affected children have mournful or Churchillian facies and a hooked nose. The benign autosomal recessive form also causes intellectual disability and joint laxity. Gastrointestinal tract hernias and diverticula are common. If the disorder is severe, progressive pulmonary emphysema may precipitate cor pulmonale. Bronchiectasis, heart failure, and aortic aneurysms can also occur.
Diagnosis of cutis laxa is clinical. There are no specific laboratory findings; however, a skin biopsy may reveal abnormalities in elastic fibers. Certain tests (eg, echocardiography, chest x-ray) may be done to check for associated conditions (eg, emphysema, cardiomegaly, heart failure) in patients with cardiopulmonary symptoms. Genetic testing is indicated for patients with early-onset cutis laxa or a suggestive family history because test results may predict the risk of transmission to offspring and of extracutaneous organ involvement.
Typical cutis laxa can be distinguished from Ehlers-Danlos syndrome because dermal fragility and articular hypermobility are absent. Other disorders sometimes cause localized areas of loose skin. In Turner syndrome, lax skinfolds at the base of an affected girl’s neck tighten and resemble webbing as she ages. In neurofibromatosis, unilateral pendular plexiform neuromas occasionally develop, but their configuration and texture distinguish them from cutis laxa.
There is no specific cutis laxa treatment. Physical therapy may sometimes help increase skin tone.
Plastic surgery considerably improves appearance in patients with hereditary cutis laxa but is less successful in those with acquired disease. Healing is usually uncomplicated, but dermal laxity may recur. Extracutaneous complications are treated appropriately.