Eruptive Pseudoangiomatosis
Eruptive pseudoangiomatosis (EP) is a rare, benign, self-limiting paraviral exanthem, a reactive rash that follows a viral infection. It is marked by the sudden appearance of small, bright red, angioma-like papules, each surrounded by a characteristic pale ring (anemic halo).
Although the lesions look like true vascular tumors, EP is actually a temporary dilation of superficial capillaries and venules in the upper dermis, with compensatory vasoconstriction in the surrounding skin. There is no proliferation or new formation of endothelial cells.
Pathogenesis and Triggers
Paraviral Etiology
EP usually appears 1–2 weeks after a respiratory or gastrointestinal viral infection. The viruses most strongly linked to it include:
- Enteroviruses: echovirus (types 25 and 32) and coxsackievirus B.
- Herpesviruses: Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus 6 (HHV-6) and human herpesvirus 7 (HHV-7).
- Other viruses: parvovirus B19, adenovirus, influenza A and SARS-CoV-2. Some cases have also been reported after insect bites.
How Vasodilation and the Anemic Halo Develop
- Superficial dermal vasodilation: Circulating immune complexes or virus-induced inflammatory cytokines act on the capillary network of the dermal papillae, dilating the superficial capillaries and causing mild swelling of the endothelial cells without increasing the number of vessels.
- Surrounding vasoconstriction: A neurovascular reflex or the local release of vasoconstrictors (such as endothelin-1) in nearby capillaries leaves a small zone of reduced blood flow around each lesion, producing the pale anemic halo around the red papule.
Clinical Features and Dermoscopy Findings
Typical Skin Lesions:
- Onset: Appears suddenly over 24–48 hours, most often in children but also in adults.
- Location: Mainly the face, neck, arms and legs; less often the trunk.
- Appearance: Bright red or orange-red macules and papules, 2–5 mm, with a smooth, shiny surface. They blanch completely under glass pressure (positive diascopy) because no blood has leaked out of the vessels.
- Anemic halo: Each red papule is ringed by a pale white band of skin 1–3 mm wide.
- Associated symptoms: Usually painless and not itchy, or only mildly itchy. There may be a history of low-grade fever, fatigue or digestive upset a few days earlier.
Dermoscopy Findings:
- Center: A red central area containing dilated but well-defined dotted vessels or vascular lacunae (dotted/lacunar vascular pattern).
- Periphery: The surrounding zone has no visible vessels and appears as a thin, bright white pale structureless zone, matching the clinical area of vasoconstriction.
Differential Diagnosis of Angioma-Like and Vascular Eruptions
| Eruptive Pseudoangiomatosis (EP) | Cherry Angioma | Bacillary Angiomatosis |
|---|---|---|
| Reactive response after a viral infection | Age-related benign proliferation of endothelial cells | Bacterial infection with Bartonella henselae |
| Always a clear anemic halo | No surrounding halo | No halo; lesions bleed easily |
| Blanches completely under glass pressure | Does not blanch completely | Does not blanch; firm lesion |
| Clears completely on its own in 2–8 weeks | Permanent, increases in number over time | Worsens without antibiotics |
How We Diagnose EP at Haute-Derma
- Clinical examination and diascopy: A clear glass slide is pressed directly onto a red papule. EP lesions flatten and lose their color completely under pressure, confirming simple vasodilation rather than purpura or a fixed vascular tumor.
- Detailed dermoscopy: Identifies the central vascular structures and the surrounding white, vessel-free ring, confirming the diagnosis without a skin biopsy.
- Viral history: We ask about fever, upper respiratory infections, diarrhea, and any vaccinations or viral illnesses in the previous 4 weeks.
Management and Treatment at Haute-Derma
Reassurance and Monitoring
- The doctor clearly explains the benign nature of the condition to the patient or parents to avoid unnecessary worry.
- The lesions fade completely on their own within 2–8 weeks, without scarring or pigment changes.
Symptomatic Care
- Itch control (if needed): A second-generation oral H1 antihistamine such as levocetirizine 5 mg/day or desloratadine 5 mg/day for 7–10 days.
- Moisturizing and barrier repair: A gentle moisturizer with ceramides, panthenol and niacinamide twice daily to soothe the skin and reduce any accompanying irritation.
- Sun protection: Broad-spectrum sunscreen SPF 30 or higher on lesions of the face and neck to protect the skin from UV exposure while it recovers.
