Paediatrics: Collagen and elastin disorders

Collagen and elastin disorders

Collagen disorders

Ehlers–Danlos syndrome

Comprises a group of several rare genetic (most autosomal dominant) disorders of collagen. In classical EDS the skin is soft, hyperextensible, easily bruised, and heals poorly with thin, atrophic ‘cigarette paper’ scars. Hypermobile EDS is characterized by soft skin with hypermobility of large and small joints. There is no specific treatment.

Striae (stretch marks)

Result from linear growth exceeding the capacity of new collagen pro-duction (e.g. pubertal growth spurt, with glucocorticoids). Linear reddish-purple marks develop. Most commonly occur on lower back and outer thighs. There is no treatment, but the marks slowly fade.

Keloid

An excessive fibrous tissue response to skin trauma. The cause is un-known, but often familial and more common in Afro-Caribbean children. Skin trauma results in well-demarcated raised, smooth, scar that extends beyond original injury.

Treatment 

Repeated intralesional triamcinolone injections are helpful if given early in keloid development. Radiotherapy also may be helpful if given early or before surgery.

Osteogenesis imperfecta

Group of several rare genetic diseases, mostly autosomal recessive, in which there is inadequate or defective collagen production.

Presentation

Frequent skeletal fractures and multiple deformities; thin skin; defective teeth; hypermobile joints; and blue sclera.

Treatment

There is no specific treatment. Supportive therapy includes use of wheel-chairs, orthoses, and analgesics for fractures, etc. Severe forms are lethal in infancy. Less severe forms lead to short stature, multiple or recurrent fractures, and deformities.

Elastin disorders

Cutis laxa

A rare congenital disorder of defective elastin that presents with loose skin folds and easily stretched skin that only slowly returns to original position. It is associated with later hernia, large vessel rupture, and em-physema.