Hypereosinophilic Syndrome Clinical Presentation

Updated: Jul 13, 2022
  • Author: Venkata Anuradha Samavedi, MBBS, MD; Chief Editor: Emmanuel C Besa, MD  more...
  • Print


Hypereosinophilic syndrome is a heterogeneous disease process; thus, it has multiple manifestations, which may occur simultaneously or individually. The presentation can be sudden and dramatic, with cardiac, neurologic, or thrombotic complications, but, more often, the onset is insidious. [23] In case series, hypereosinophilic syndrome was discovered as an incidental finding in 12% and 6% of patients. [24, 25]

Virtually any organ system may be involved in hypereosinophilic syndrome, but the heart, central nervous system (CNS), skin, and respiratory tract are commonly involved. Thromboembolic disease is not infrequent. Many patients experience fever and night sweats. Some sources identify anorexia and weight loss as common presenting manifestations; however, other sources report that these signs and symptoms do not usually occur unless underlying cardiac disease is present.

Cardiac manifestations

The cardiac system is one of the most frequently involved systems, and cardiac complications are a leading cause of mortality. Damage typically occurs in three stages: (1) initial acute necrosis early in the disease process that typically has no clinical manifestations but may occasionally be severe enough to cause symptoms; (2) thrombotic phase; and (3) endomyocardial fibrosis. Common symptoms in these phases include chest pain, dyspnea, or orthopnea.

Hematologic manifestations

Hematologic manifestations are largely nonspecific and may include fatigue, which may be due to the anemia that is occasionally observed with hypereosinophilic syndrome. Left upper quadrant pain may indicate splenomegaly, which occurs in about 40% of patients. Thrombotic episodes occur frequently and often present as neurologic symptoms. The thrombotic events may occur solely due to cardiac disease, or they may be caused by hypercoagulability. The mechanism of hypercoagulability is unknown.

Neurologic manifestations

Embolic or thrombotic strokes or transient ischemic episodes may occur and are often the initial manifestations of hypereosinophilic syndrome.  Some patients with hypereosinophilic syndrome experience an encephalopathy caused by CNS dysfunction. Blurred vision and slurred speech have also been reported,

Peripheral neuropathies account for about 50% of all neurologic symptoms in hypereosinophilic syndrome. Patients may report symmetric or asymmetric sensory changes, pure motor deficits, or mixed sensory and motor complaints.

Respiratory manifestations

The most benign variant of hypereosinophilic syndrome involves eosinophilic infiltrates in the bases and periphery of the lungs, according to one source. Patients often have recurrent angioedema.  A chronic, persistent cough, usually nonproductive, is the most common respiratory symptom reported in hypereosinophilic syndrome. [26]  Rhinitis is sometimes a presenting feature.

Dyspnea may occur due to congestive heart failure (CHF) or pleural effusions (which are not always secondary to CHF).  Less frequently, pulmonary fibrosis occurs after prolonged disease and often accompanies cardiac fibrosis.

Bronchospasm and asthmatic symptoms are infrequent.

Other systemic manifestations 

Other signs and symptoms may include the following:

  • Rheumatologic – Arthralgias and myalgias are frequent complaints. Raynaud phenomenon occurs but is infrequent.
  • Dermatologic – Skin involvement is common and nonspecific; the most common symptom is pruritus. [27] Dermatographism and angioedema are also frequently present.
  • Gastrointestinal – Diarrhea is a relatively common complaint, occurring in approximately 20% of patients with hypereosinophilic syndrome. Nausea and abdominal pain are also common complaints. Some patients present with sclerosing cholangitis. Occasionally, small-bowel necrosis due to microthrombi can occur.

Physical Examination

The physical findings of hypereosinophilic syndrome are varied and parallel the clinical history.

Cardiac findings are as follows:

  • Evidence of chronic heart failure (CHF) becomes prominent with advanced hypereosinophilic syndrome and is an ominous sign
  • Various murmurs may be heard, especially mitral or tricuspid regurgitation
  • Splinter hemorrhages are often observed with cardiac involvement
  • Physical findings typical of restrictive heart disease can be expected

Hematologic findings include splenomegaly in approximately 40% of patients.

Neurologic findings are as follows:

  • Physical findings associated with stroke and transient ischemic attacks can be observed
  • When peripheral neuropathy is present, findings may be purely sensory, entirely motor, or a combination of both
  • Deficits are often symmetric
  • Mononeuritis multiplex and muscle atrophy due to radiculopathy are sometimes encountered
  • Generalized weakness is observed but is less specific

Pulmonary findings are as follows:

  • Rales may accompany infiltrates and fibrosis
  • Findings typical of CHF with effusion may also be encountered
  • Angioedema is often a prominent feature associated with pulmonary involvement

Rheumatologic findings are as follows:

  • Large joint effusions can occur
  • Digital necrosis is rare but sometimes observed with associated Raynaud phenomenon

The skin is among the most common organ systems involved in hypereosinophilic syndrome; more than half of all patients have cutaneous involvement. In a minority of reports, skin involvement is the only manifestation of hypereosinophilic syndrome.

Most skin eruptions fall into two patterns. One pattern is angioedematous or urticarial and associated with a benign prognosis. The other pattern is erythematous, pruritic papules, plaques, and nodules, with or without ulceration. A special form of urticaria is dermatographism, which occurs in up to 75% of affected patients.

Less common cutaneous manifestations include the following:

  • Erythroderma
  • Erythema annulare centrifugum
  • Erythema gyratum repens
  • Mucosal ulcerations

Note the images below.

Indurated edematous plaques of hypereosinophilic syndrome on a patient's legs.

Indurated edematous plaques of hypereosinophilic s Indurated edematous plaques of hypereosinophilic syndrome on a patient's legs.

Erythroderma in a patient with hypereosinophilic syndrome.

Erythroderma in a patient with hypereosinophilic s Erythroderma in a patient with hypereosinophilic syndrome.

Gastrointestinal findings are as follows:

  • Hepatomegaly may occur with chronic active hepatitis due to hypereosinophilic syndrome
  • Hepatomegaly may also occur with Budd-Chiari syndrome, which may infrequently be a thrombotic complication of hypereosinophilic syndrome