“Ehlers Danlos syndrome (EDS) is a group of hereditary connective tissue disorders that manifests clinically with skin hyperelasticity, hypermobility of joints, atrophic scarring, and fragility of blood vessels. It is largely diagnosed clinically, although identifying the gene encoding the collagen or proteins interacting with it is necessary to identify the type of EDS. Identifying the type of EDS to guide management and counseling is important. In 2017, a new international classification of EDS was proposed with 13 different variants. This syndrome is heterogeneous and has been classified into six types (classical, vascular, hypermobile, arthrochalasis, kyphoscoliotic, and dermatosparaxis), with the causative collagen pathology being different for each type.

The pathophysiology of most Ehlers Danlos syndrome subtypes involves heritable mutations in collagen synthesis and/or processing. The inheritance pattern of these mutations is variable, including autosomal dominant and recessive inheritance involving different mutations; however, it is worth noting that there are reports of spontaneous mutations causing identical genotypes and phenotypes. The collagen affected by these mutations is integral to every body system, from the skin to the integrity of the vasculature, and as such, the symptoms of the disease can be variable and widespread.

The skin is usually white in color and soft to the touch, and underlying vessels can become apparent. The skin has a doughy feel and is easily hyperextensible. It is easily stretchable and immediately returns to its original state after release. Molluscoid pseudotumors are small, spongy outgrowths observed over scars and pressure points. They are commonly found in patients with type I EDS.

Smaller, deep, and movable nodules are often palpable in the subcutaneous tissue. They can be observed in the arms and over the tibia. Radiography may reveal calcification. The fragility of dermal skin with frequent bruises and lacerations is common. The joints are hyperextensible, but the degree of involvement varies. The digital joints are most commonly influenced, but alterations can be present in all the joints.”

National Library of Medicine-NIH (https://www.ncbi.nlm.nih.gov/books/NBK549814/)