Table of ContentsDefinition / general | Essential features | Epidemiology | Etiology | Clinical features | Treatment | Clinical images | Microscopic (histologic) description | Microscopic (histologic) images | Differential diagnosis | Board review style question #1 | Board review style answer #1
Cite this page: Dubyk F, Elwood HR. Wells syndrome. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skinnontumorwellssyndrome.html. Accessed May 16th, 2021.
Definition / general
- Idiopathic inflammatory dermatitis with eosinophilic infiltration
- Also known as eosinophilic cellulitis
- Idiopathic condition typically characterized by recurrent pruritic to painful plaques that often clinically resemble cellulitis
- Histopathology characterized by a prominent eosinophilic infiltrate with "flame figures"
- Equal prevalence in men and women
- Most cases sporadic
- Higher prevalence in adults than children
- Some cases may be secondary to hypersensitivity reaction to insect bites, medications, infections, vaccinations, malignant tumors or myeloproliferative disorders (J Clin Aesthet Dermatol 2011;4:55)
- Clinical picture is variable but most often recurrent bouts of edematous nodules and plaques, often preceded by prodromal itching or pain
- Usually a limited course over weeks to month but often recur
- May resemble cellulitis clinically but not warm or tender (Postepy Dermatol Alergol 2014;31:322) and does not improve with antibiotics (J Clin Aesthet Dermatol 2011;4:55)
- Erythematous papules, plaques or nodules that may be painful or pruritic (Postepy Dermatol Alergol 2014;31:322)
- Sometimes annular configuration, can blister
- May be single or multiple
- Peripheral blood eosinophilia common (found in 67% of cases) (Can J Plast Surg 2012;20:91)
- Leukocytosis (found in 41% of cases)
- Oral or topical corticosteroids most commonly, often with dramatic improvement
- Antihistamines and immunomodulatory agents also used for refractory or unresponsive cases
Microscopic (histologic) description
- Diffuse dermal infiltrate of perivascular and interstitial eosinophils throughout superficial and deep dermis, often with extension into subcutis
- Admixed histiocytes and lymphocytes
- Old lesions may show granulomas
- Flame figures often present (deposition of eosinophil basic protein on collagen bundles)
- Can have subepidermal edema, sometimes with blister formation
- May have eosinophilic spongiosis
- No vasculitis
Microscopic (histologic) images
Contributed by Favia Dubyk, M.S., M.D.
Images hosted on other servers:
- Bacterial cellulitis: dermal to subcutaneous infiltrate of neutrophils, often with superficial dermal edema; typically lacks flame figures and neutrophils predominate over eosinophils
- Churg-Strauss syndrome: may have similar eosinophilic granulomas, vasculitis not always present in skin biopsy, clinical correlation helpful
Board review style question #1
Which of the following are TRUE of Wells syndrome:
- Flame figures are pathognomonic
- Granulomatous inflammation always absent
- Lesions can clinically resemble cellulitis
- Peripheral blood eosinophilia is required for diagnosis
- Vasculitis usually present
Board review style answer #1
C. Often clinically resembles cellulitis, hence it's other name "eosinophilic cellulitis".
Reference: Wells syndrome
- False: while flame figures are a hallmark of the disease, these can sometimes be seen in a number of other settings such parasite infestation, arthropod bite, drug reaction, allergic contact dermatitis and bullous pemphigoid.
- False: older lesions can have a granulomatous component, sometimes with prominent giant cells.
- False: seen in up to 67% of patients but not required for diagnosis.
- False: vasculitis typically absent although there may be extravasated erythrocytes.
Reference: Wells syndrome