Introduction 

Definition 

Finding out you have a rare and often fatal condition with no cure has been the case for 200 people reported worldwide diagnosed with degos disease (DD).¹ DD often presents with skin lesions containing an atrophic white porcelain centre.¹

Why does this topic matter?

There are far too many occlusive vessel disorders to be able to establish an exact number of them. This can cause an issue of misdiagnosis due to the number of similar disorders. Moreover, DD can occur in two forms: cutaneous form or systemic form,¹ with the latter often being fatal. It is crucial that doctors and allied health care professionals can distinguish between occlusive vessel disorders to provide accurate diagnosis and patient-specific management and treatment. 

This article covers how DD is distinct from other disorders that are also occlusive, such as in pathogenesis, clinical presentation, and prognosis. 

The pathophysiology of degos disease

The mechanism of DD remains unclear, with only 200 cases reported worldwide,  highlighting its extreme rarity.¹ However, researchers and scientists do know that DD is a condition of vascular occlusion. This is where small-sized arteries become blocked, resulting in a hindered blood supply to the organs. Moreover, scientists have also suggested that the inner lining of arteries and arterioles, which comprises endothelial cells, is attacked by the immune system.² This causes narrowing of the vessels and swelling, which results in blood clots, therefore leading to ischemia. As ischemia becomes more severe, the damage increases. Prolonged ischemia leads to multisystem effects in the skin, the gastrointestinal system (GI tract), and the central nervous system.³ This can cause complications such as bleeding in the GI tract, vision changes, strokes, and seizures, depending on the organs involved. 

Scientists have also highlighted the involvement of C5b-9, which has been found in large deposits in the skin, GI tract, and parts of the brain in patients with the systemic form of DD.³ C5b-9 is a protein complex which forms at the end of a complement system cascade, which is a part of the immune system.⁴ This develops on cell membranes, triggering cell lysis. 

Clinical manifestations 

As previously mentioned, DD exists in two distinct forms: the cutaneous form or the systemic form (often fatal). The cutaneous form solely affects the skin and presents with skin lesions.⁵ Moreover, it is said to have a satisfactory prognosis for patients with DD. However, the systemic form affects multiple organs, and death usually occurs 2-3 years after the initial onset of the disease.⁶ This is because of the systemic damage it causes, such as bowel perforation or significant cerebral haemorrhage ⁵ In this form, the organs commonly affected in decreasing order are the GI tract, CNS, thoracic organs, and kidney.⁷ 

Comparison with other occlusive disorders

Antiphospholipid syndrome

Antiphospholipid syndrome (APS) is considered an autoimmune condition, where the immune system induces abnormal antibodies termed “antiphospholipid antibodies.”⁸ This results in the excess accumulation of blood clots, also known as hypercoagulability.⁸ As a result of the recurrent blood clots, patients with APS are at increased risk of developing deep vein thrombosis (DVT), stroke, and pulmonary embolism.⁸ Pregnant patients are also more likely to have miscarriages.⁸ (Table 1). 

Laboratory tests are key in identifying patients with APS.⁸ Although DVT, recurrent blood clots, and miscarriages can highlight suspicion of APS, it still needs to be confirmed through a positive test, which detects the presence of anti-phospholipid proteins. The most commonly used techniques are:⁸

• ELISA: to measure antiphospholipid proteins, such as aCL, in the blood. If aCL is consistently present at least 12 weeks apart, then it strongly supports the diagnosis
• Coagulation-based assays: Used to measure LA in a blood sample, which is a very important indicator of APS

Buerger's disease

Buerger's disease is an inflammatory disease that also affects small and medium-sized arteries and veins of the upper and lower body.⁹ The cause of the disease is not definitive, but exposure to tobacco is required for both the initiation and progression of this disease.⁹

Unlike DD, there is an absence of white porcelain skin lesions in Buerger's disease. As the white porcelain skin lesions are common in both forms of DD, their presence can be utilised to distinguish it from Buerger’s, as there is no specific laboratory test for Buerger's.⁹

Polyarteritis nodosa

Polyarteritis nodosa (PAN) is another rare inflammatory disorder that causes cell wall death in small-sized arterial vessels. ¹⁰ This causes narrow and hindered blood flow that can result in organ impairment. Although no definitive laboratory test exists for PAN, you can test for elevated levels of C-reactive protein and erythrocyte sedimentation rate, which would indicate inflammation, which is not present in DD. ¹⁰ 

Table 1: Highlights and compares the differences in occlusive vessel disorders to DD.

Management and prognosis

As previously mentioned, there is no definitive cure for DD. Depending on the form of DD, different management options are available. Management should primarily focus on symptomatic control and support for patients. 

In the cutaneous form of DD, the prognosis is typically good. The disease does not go beyond the skin, and internal organs are not damaged. Therefore, management usually consists of support and antiplatelet,¹  therapy to reduce the risk of clotting in skin lesions. 

However, treatment is heavier for patients diagnosed with the systemic form of DD. Patients with the systemic form have a higher mortality rate; death occurs months to 3 years after the onset of the disease. This is because the disease goes beyond the skin and into internal organs such as the GI tract and CNS. Antiplatelets and anticoagulants can be used to reduce the risk of blood clots, but are not very effective.¹ Supportive care is essential for managing complications in surgery for bowel perforation, strokes, and seizures. 

Newer treatments 

Studies have highly suggested that patients with the systemic form of DD should start on eculizumab and treprostinil as soon as possible.¹¹ The former has shown benefit by hindering injury to endothelial cells. Treprostinil has also been used to improve blood flow. Both of these together have shown the largest improvement in patients with systemic form in comparison to antiplatelet and anti-coagulation therapies.¹¹ 

Summary 

DD is a complicated condition, and its extreme rarity only makes it more difficult to treat. However, patients who have DD and doctors involved in their care must be able to identify it from other occlusive vessel disorders. Especially in the case of systemic DD, efficient and accurate diagnosis is needed to allow faster treatment and better patient outcomes. As systemic DD is associated with high mortality, it is important to distinguish it from its cutaneous form. DD is not solely a clotting or smoking-related condition, unlike APS and Buerger's disease. Moreover, it also does not typically show systemic inflammation as seen in PANS. New therapies such as eculizumab and treprostinil have provided hope for systemic DD, but further research is needed to gain a better understanding. Overall, identifying DD can improve patient outcomes but also enhance our knowledge and understanding of blocked vessels and endothelial injury.