Wells Syndrome, also known as Eosinophilic cellulitis, is a rare inflammatory disorder of the skin. It is characterized by recurring episodes of deep, tender swelling that often resemble a bacterial skin infection. First described in 1971, this uncommon dermatosis affects both children and adults.
Clarifying the Nature of Wells Syndrome
Wells Syndrome is fundamentally a disorder of the immune system and is neither infectious nor contagious. It cannot be passed from person to person through physical contact, shared objects, or airborne transmission. The condition is classified as an auto-inflammatory or hypersensitivity reaction, driven by the body’s own immune response.
The inflammation is caused by an excessive accumulation of eosinophils, a specific type of white blood cell. These immune cells infiltrate the skin layers, releasing toxic proteins that cause tissue damage and swelling. Since the mechanism is an internal immune malfunction, there is no risk of transmission.
Recognizing the Signs
The onset of Wells Syndrome is typically sudden, often beginning with a localized sensation of burning or intense itching. This is quickly followed by the development of large, raised, red, and swollen patches that mimic acute bacterial cellulitis. These plaques are firm to the touch and may sometimes be covered with small blisters or vesicles.
Over several days, the lesions often expand and evolve, sometimes adopting a ring-shaped or annular configuration. As the inflammation subsides, the affected skin may change color, progressing through shades of brown-red, blue-gray, and eventually greenish-gray.
A skin biopsy is typically performed for diagnosis. The biopsy reveals a massive infiltration of eosinophils and characteristic formations known as “flame figures.” These microscopic structures form when collagen fibers in the skin become coated with granular debris released by the dying eosinophils.
Potential Causes and Underlying Mechanisms
The precise cause of Wells Syndrome remains unknown in many cases, leading to its classification as idiopathic. However, it is understood to be an inappropriate and localized hypersensitivity reaction involving eosinophils. Researchers hypothesize that abnormal regulation causes eosinophils to accumulate and degranulate within the skin tissue, and a variety of external and internal factors are implicated as potential triggers for this excessive immune response.
Common Triggers
Common triggers include:
- Insect bites, particularly from arthropods.
- Certain medications.
- Specific vaccinations.
- Underlying infections (viruses, fungi, or parasites).
- Serious internal conditions, such as certain hematologic disorders (in rare instances).
Management and Clinical Course
The primary treatment for managing acute inflammatory episodes of Wells Syndrome is a short course of systemic corticosteroids, such as oral prednisone. This medication works by suppressing the overactive immune response, which reduces the eosinophil-driven inflammation and swelling. While corticosteroids successfully resolve symptoms, they are not a cure for the condition.
For less severe episodes or as part of a tapering regimen, topical corticosteroids may be used alongside oral antihistamines to manage associated itching (pruritus). Alternative therapies, including dapsone or immunosuppressants like cyclosporine, may be utilized for cases resistant to standard steroid treatment.
The clinical course is typically benign, with individual episodes resolving completely without scarring within four to six weeks. However, the condition is often recurrent, with flares reappearing months or years after the initial presentation.