Cold-reactive autoimmune hemolytic anemia (AIHA) is rare among the hemolytic anemias. It results when 1 of a variety of processes causes the generation of immunoglobulin M (IgM) autoantibodies against endogenous erythrocytes, resulting in complement activation and predominantly intravascular hemolysis. Cold AIHA is typically a primary lymphoproliferative disorder with marrow B-cell clones producing pathogenic IgM. More rarely, secondary cold AIHA (cAIHA) can develop from malignancy, infection, or other autoimmune disorders. However, in children cAIHA is typically post infection, mild, and self-limited. Symptoms include a sequelae of anemia, fatigue, and acrocyanosis. The severity of disease is variable and highly dependent on the thermal binding range of the autoantibody. In adults, treatment has most commonly focused on reducing antibody production with rituximab-based regimens. The addition of cytotoxic agents to rituximab improves response rates, but at the expense of tolerability. Recent insights into the cause of cold agglutinin disease as a clonal disorder driven by complement form the basis of newer therapeutic options. While rituximab-based regimens are still the mainstay of therapy, options have now expanded to include complement-directed treatments and other B-cell-directed or plasma-cell-directed therapies.

Secondary acrocyanosis after spinal cord injury is extremely rare. We describe a case with secondary acrocyanosis in a complete T12 paraplegic patient. A 41-year-old man with complete T12 paraplegia after a gunshot wound to the thoracic spine 20 years prior presented with a four-month history of bilateral foot bluish discoloration precipitated when he sat with his legs down, improving rapidly after a few minutes of leg elevation. Changes in the skin color of the lower extremities were evaluated in the seated position for two hours. The skin color became darker, progressing to a bluish discoloration through the entire length of the legs. After two hours, the feet and most of the legs appeared deep purple. The color of the legs returned to their baseline three minutes later after the patient was placed supine in the bed. The diagnosis of secondary acrocyanosis due to the T12 spinal cord injury was established based on the physical examination and ancillary tests showing no peripheral ischemia. Other causes of secondary acrocyanosis were excluded during the work-up. This report presents the first case of a paraplegic patient with spinal cord injury presenting secondary acrocyanosis.

Vascular acrosyndromes are characterized by sparse, uniform clinical manifestations and a variety of possible pathomechanisms. The present article focuses on the functional entities. Raynaud phenomenon is based on cold- or stress-induced vasospasms of acral arteries. It is defined by the color changes of the skin, in the typical case white-blue-red (tricolore). The long fingers are most commonly affected. The etiology is unknown, and the pathophysiology is poorly understood. A distinction is made between primary and a secondary Raynaud phenomenon. The most important underlying diseases include collagenosis, primarily systemic sclerosis, and malignancies; furthermore, medications and drugs may promote vasospasm. Treatment is aimed at preventing or breaking the vasospasm, but has been only partially effective in doing so. Acrocyanosis is a vasospastic dystonic acral disorder that results in permanent reddish-livid discoloration, especially of the hands and feet. Secondary forms occur in collagenosis, malignancies, and myelodysplastic syndromes. The etiology and pathophysiology are virtually unknown. Targeted pharmacological intervention is not possible. Unlike all other vascular acrosyndromes, erythromelalgia is characterized by hyperemia. The primary form is a genetic sodium channelopathy, while secondary forms include malignancies, connective tissue diseases, and myelodysplastic syndromes. The symptoms are often distressing and disabling. Therapy requires a multimodal approach that includes both nonpharmacological and pharmacological strategies. Close interdisciplinary collaboration is essential for the management of this disease.

Paroxysmal vascular acrosyndromes are related to a peripheral vasomotor disorder and presented as paroxysmal color changes of the fingers. They include primary Raynaud's phenomenon (RP), which is the most common, secondary RP and erythermalgia. They are to be distinguished from non-paroxysmal acrosyndromes such as acrocyanosis and chilblains, which are very frequent and often associated with RP, digital ischemia and necrosis, spontaneous digital hematoma and acrocholosis. The challenge of a consultation for a vascular acrosyndrome is to make positive diagnosis through history and clinical examination, and to specify its nature, to prescribe complementary exams. In any patient consulting for RP, assessment includes at least an antinuclear antibody test and capillaroscopy. For erythermalgia, a blood count and even a search for JAK2 mutation are required. A thryoid-stimulating hormon assay, a test for antinuclear antibodies, and a search for small fiber neuropathy are also performed. The treatment of RP is essentially documented for secondary RP where calcium channel blockers are indicated in first line, and iloprost in severe cases. The treatment of primitive erythermalgia is based on sodium channel blockers such as mexiletine or lidocaine infusions, and on drugs effective on neuropathic pain, such as gabapentin or amitryptiline, in case of erythermalgia associated with small fiber neuropathy. The treatment of erythermalgia associated with myeloproliferative syndromes is based on etiological treatment and aspirin.

Sutimlimab, a first-in-class humanized immunoglobulin G4 (IgG4) monoclonal antibody that selectively inhibits the classical complement pathway at C1s, rapidly halted hemolysis in the single-arm CARDINAL study in recently transfused patients with cold agglutinin disease (CAD). CADENZA was a 26-week randomized, placebo-controlled phase 3 study to assess safety and efficacy of sutimlimab in patients with CAD without recent (within 6 months prior to enrollment) transfusion history. Forty-two patients with screening hemoglobin ≤10 g/dL, elevated bilirubin, and ≥1 CAD symptom received sutimlimab (n = 22) or placebo (n = 20) on days 0 and 7 and then biweekly. Composite primary endpoint criteria (hemoglobin increase ≥1.5 g/dL at treatment assessment timepoint [mean of weeks 23, 25, 26], avoidance of transfusion, and study-prohibited CAD therapy [weeks 5-26]) were met by 16 patients (73%) on sutimlimab, and 3 patients (15%) on placebo (odds ratio, 15.9 [95% confidence interval, 2.9, 88.0; P < .001]). Sutimlimab, but not placebo, significantly increased mean hemoglobin and FACIT-Fatigue scores at treatment assessment timepoint. Sutimlimab normalized mean bilirubin by week 1. Improvements correlated with near-complete inhibition of the classical complement pathway (2.3% mean activity at week 1) and C4 normalization. Twenty-one (96%) sutimlimab patients and 20 (100%) placebo patients experienced ≥1 treatment-emergent adverse event. Headache, hypertension, rhinitis, Raynaud phenomenon, and acrocyanosis were more frequent with sutimlimab vs placebo, with a difference of ≥3 patients between groups. Three sutimlimab patients discontinued owing to adverse events; no placebo patients discontinued. These data demonstrate that sutimlimab has potential to be an important advancement in the treatment of CAD. This trial was registered at www.clinicaltrials.gov as #NCT03347422.

In this Part 2 of a 2-part continuing medical education series, we review the epidemiology of peripheral vascular disease, its association with cutaneous symptoms, and the diagnosis and evaluation of cutaneous features of vascular disorders. As peripheral vascular disease becomes more prevalent globally, it is essential for dermatologists to become competent at accurately recognizing and diagnosing cutaneous manifestations and directing individuals to receive appropriate care and treatment.

Ethylmalonic encephalopathy (MIM #602473) is a rare autosomal recessive metabolic condition caused by biallelic variants in ETHE1 (MIM #608451), characterized by global developmental delay, infantile hypotonia, seizures, and microvascular damage. The microvascular changes result in a pattern of relapsing spontaneous diffuse petechiae and purpura, positional acrocyanosis, and pedal edema, hemorrhagic suffusions of mucous membranes, and chronic diarrhea. Here, we describe an instructive case in which ethylmalonic encephalopathy masqueraded as meningococcal septicemia and shock. Ultrarapid whole-genome testing (time to result 60 h) and prompt biochemical analysis facilitated accurate diagnosis and counseling with rapid implementation of precision treatment for the metabolic crisis related to this condition. This case provides a timely reminder to consider rare genetic diagnoses when atypical features of more common conditions are present, with an early referral to ensure prompt biochemical and genomic diagnosis.

After reading with great interest the article entitled: "Exploring the impact of the COVID-19 pandemic on provision of cardiology services: a scoping review" redacted by Farah Yasmin et al., published by Reviews in Cardiovascular Medicine, we would like to add the following thoughts. Acute respiratory distress syndrome (ARDS) in Coronavirus disease 2019 (COVID-19) and pulmonary insufficiency reduces blood oxygen saturation and results in hypoxia. Therefore, the determining factor in the survival of patients with COVID-19 is their resistance to hypoxia. At the same time, it is the cardiovascular system that is an important and very sensitive link in the human adaptation to hypoxia. That is why it is necessary to carefully study the relationship between diseases of the heart, blood vessels, the reactivity of the cardiovascular system to hypoxia, and mortality in patients who develop ARDS with COVID-19.

Acrocyanosis triggered by standing position as the main sign of postural orthostatic tachycardia (POTS) is little known but well described in scientific literature. In pediatric age, POTS is defined as orthostatic intolerance that is accompanied by an excessive increase in heart rate without arterial hypotension. We present two clinical reports of teenagers who were admitted in the Emergency Department with acrocyanosis and orthostatic intolerance. The first patient was 13-year-old and had an increase in heart rate of 40 bpm when moving from a reclining to a standing position. The second patient was 14-year-old and showed an increasing in heart rate up to 125 bpm after upright position. In both patients' blood pressure was normal and all investigations were negative. They were finally diagnosed with Acrocianosis como primera manifestación de síndrome de taquicardia postural ortostática en dos adolescentes Acrocyanosis as the first manifestation of orthostatic postural tachycardia syndrome in two adolescents postural orthostatic tachycardia. Recognizing acrocyanosis as first sign of this disease is useful for diagnosis and can help to avoid unnecessary testing.

Pathogenic gain-of-function variants in complement Factor B were identified as causative of atypical Hemolytic Uremic syndrome (aHUS) in 2007. These mutations generate a reduction on the plasma levels of complement C3. A four-month-old boy was diagnosed with hypocomplementemic aHUS in May 2000, and he suffered seven recurrences during the following three years. He developed a severe hypertension which required 6 anti-hypertensive drugs and presented acrocyanosis and several confusional episodes. Plasma infusion or exchange, and immunosuppressive treatments did not improve the clinical evolution, and the patient developed end-stage renal disease at the age of 3 years. Hypertension and vascular symptoms persisted while he was on peritoneal dialysis or hemodialysis, as well as after bilateral nephrectomy. C3 levels remained low, while C4 levels were normal. In 2005, a heterozygous gain-of-function mutation in Factor B (K323E) was found. A combined liver and kidney transplantation (CLKT) was performed in March 2009, since there was not any therapy for complement inhibition in these patients. Kidney and liver functions normalized in the first two weeks, and the C3/C4 ratio immediately after transplantation, indicating that the C3 activation has been corrected. After remaining stable for 4 years, the patient suffered a B-cell non-Hodgkin lymphoma that was cured by chemotherapy and reduction of immunosuppressive drugs. Signs of liver rejection with cholangitis were observed a few months later, and a second liver graft was done 11 years after the CLKT. One year later, the patient maintains normal kidney and liver functions, also C3 and C4 levels are within the normal range. The 12-year follow-up of the patient reveals that, in spite of severe complications, CLKT was an acceptable therapeutic option for this aHUS patient.

Vasospastic disorders are prevalent in the general population and can affect individuals of any age. Primary (or idiopathic) vasospastic disorders often have a benign course; treatment focuses on the control of symptoms. Secondary vasospastic disorders occur owing to an underlying condition and have an increased risk of complications, including tissue loss and digital ulcerations; treatment should focus on the underlying condition. In this review, we discuss the pathophysiology, clinical presentation, diagnosis, and management of vasospastic disorders, including Raynaud syndrome, acrocyanosis, livedo reticularis, and pernio.

The association between central nervous (CNS) stimulants used to treat attention deficit hyperactivity disorder (ADHD) and Raynaud's phenomenon (RP) has received little attention to date. Our aim was to map the existing literature on aetiopathogenesis, clinical presentation and management of peripheral vasculopathy, with a focus on RP, secondary to drug therapy for ADHD. We searched the PubMed® database (01/11/1951 to 01/08/2020) and included articles written in English, which focussed on CNS stimulants used to treat ADHD and RP. The search identified 150 articles 9 of which were eligible for inclusion (70 patients). The majority of studies (n = 6) related to children or adolescents; however, adult cases were also identified. Peripheral vascular manifestations included attacks of RP (new and worsening) and cold sensitivity (acrocyanosis and perniosis). Irreversible ischaemic complications including digital autoamputation and lower limb critical digital ischaemia have also been reported. The implicated causative CNS stimulants were Methylphenidate (n = 5), Dextroamphetamine (n = 4), Atomoxetine (n = 2), and Lisdexamphetamine (n = 2). Complete resolution of RP symptoms was observed in half (n = 5) of studies upon drug cessation. Other therapeutic strategies have included dose reduction and switching to an alternative drug therapy. A potential autoimmune association has also been postulated including drug-induced autoimmunity and new cases of systemic sclerosis which have been potentially attributed to treatment. Future research is required to understand the association between CNS stimulant drug therapies for ADHD and peripheral vascular manifestations, including RP.

Numerous cases of chilblains have been observed in the course if the COVID-19 pandemic. The aims of this study were to provide comprehensive follow-up data for patients reporting chilblains, and to determine the risk factors for incomplete recovery. Patients referred to 5 hospitals in France between March and May 2020 for chilblains were surveyed on December 2020. A teleconsultation was offered. Among 82 patients reporting chilblains, 27 (33%) reported complete recovery, 33 (40%) had recurrences of chilblains after their hands and feet had returned to normal, and 22 (27%) developed persistent acral manifestations, mostly acrocyanosis, with or without further recurrences of chilblains. Most recurrences of chilblains occurred during the following autumn and winter. A past history of chilblains was not associated with recurrences or persistent acral manifestations. Women had a significantly higher risk of developing recurrences or persistent acral manifestations (odds ratio 1.30; 95% confidence interval 1.06-1.59). In conclusion, two-thirds of patients reporting chilblains at the start of the COVID-19 pandemic experienced persistent or recurrent acral manifestations after a 10-month follow-up.

Waldenstrom macroglobulinemia (WM), a rare malignant disorder, occurs as a result of abnormal proliferation of lymphocytes that produce immunoglobulin M. In rare cases, WM complicates by type I cryoglobulinemia. Type I cryoglobulinemia usually presents with cutaneous manifestations such as Raynaud's phenomenon, purpura, necrosis, and gangrene. Various medical conditions, including thrombotic events, rheumatologic disorders, and malignancies, may present with skin discoloration and necrosis. Patients suffering from malignant diseases who initially present with skin manifestations usually are misdiagnosed by physicians. Here, we describe a 72-year-old man presenting with a 6-month acrocyanosis and progressive skin necrosis who was misdiagnosed by physicians. Finally, he was diagnosed to have WM associated with type I cryoglobulinemia. Though uncommon, hematologic malignancies can present with cutaneous manifestations. In some cases, patients may manifest with skin disorders alone. Early and prompt treatment of these diseases may save the patient life, relieve patient symptoms, and increase life quality.

To familiarize wound care practitioners with the differential diagnoses of chilblains-like lesions that could be associated with the complications of COVID-19.