What could cause telangiectasia on the back of an ear?

Telangiectasia on the Back of the Ear: Differential Diagnosis

Telangiectasia on the back of the ear most commonly results from chronic sun exposure (actinic damage), but you must systematically exclude hereditary hemorrhagic telangiectasia (HHT), prior radiation therapy, and underlying systemic conditions before attributing it to benign causes.

Primary Diagnostic Considerations

Hereditary Hemorrhagic Telangiectasia (HHT)

• Apply the Curaçao diagnostic criteria immediately: spontaneous/recurrent epistaxis, multiple telangiectasias at characteristic sites (lips, oral cavity, fingers, nose, ears), visceral arteriovenous malformations, or first-degree relative with HHT 1, 2
• HHT is definite with 3 criteria, possible with 2 criteria, and unlikely with fewer than 2 1, 2
• Telangiectasias in HHT develop on mucosal surfaces and skin, including the ears, due to enlarged vessels with thin walls prone to rupture 1, 2
• If recurrent bilateral nosebleeds or family history of nosebleeds exists, HHT becomes the leading diagnosis and requires referral to a specialist with HHT expertise 1
• The prevalence is approximately 1 in 5,000-18,000 individuals, making it underdiagnosed with frequent diagnostic delays 1, 2

Radiation-Induced Telangiectasia

• Inquire specifically about prior radiation therapy to the head/neck region, as radiation-induced telangiectasias develop in irradiated tissues and can appear years after treatment 1
• The dose of radiotherapy determines telangiectasia risk, with lesions often healing spontaneously over 5-10 years 1
• These telangiectasias reflect chronic ischemic changes in previously irradiated tissues 1

Chronic Sun Exposure (Actinic Telangiectasia)

• This is the most common cause in adults with isolated ear telangiectasias, particularly on sun-exposed areas like the posterior ear 3
• Telangiectasias arise from chronic UV damage causing vessel dilation and wall thinning 3
• Look for additional signs of photodamage: solar lentigines, actinic keratoses, skin atrophy 3

Secondary Systemic Causes to Exclude

Ataxia Telangiectasia

• Telangiectasias appear in childhood (typically by age 5) with progressive neurological deterioration including ataxia, oculomotor apraxia, and immunodeficiency 1
• This diagnosis is unlikely if neurological symptoms are absent and telangiectasias appeared in adulthood 1

Chronic Topical Corticosteroid Use

• Ask about prolonged topical steroid application to the ear area, which causes skin atrophy and telangiectasia development 3
• This is a secondary cause following iatrogenic skin injury 3

Generalized Essential Telangiectasia (GET)

• GET presents with widespread, symmetric telangiectasias on extremities and trunk, not isolated to one ear 4
• This idiopathic syndrome is a diagnosis of exclusion after ruling out other causes 4

Diagnostic Algorithm

1. Screen for HHT using Curaçao criteria 1, 2:

   • Ask about recurrent nosebleeds (present in >90% of HHT adults) 1
   • Examine lips, oral mucosa, tongue, hard palate, and fingers for additional telangiectasias 1
   • Obtain family history of HHT or recurrent nosebleeds 1, 2
   • If ≥2 criteria present, refer to HHT specialist and consider genetic testing for ENG, ACVRL1, and SMAD4 mutations 2

2. Obtain detailed exposure history 3:

   • Prior radiation therapy to head/neck region 1
   • Chronic sun exposure patterns 3
   • Prolonged topical corticosteroid use 3

3. Assess for systemic disease markers 3:

   • Neurological symptoms suggesting ataxia telangiectasia 1
   • Distribution pattern (isolated vs. widespread) 4

Critical Pitfalls to Avoid

• Never dismiss isolated ear telangiectasias without screening for HHT, as this represents a potentially life-threatening condition with asymptomatic arteriovenous malformations that can cause stroke or cerebral abscess 1, 2
• Do not perform skin biopsy of suspected HHT telangiectasias without first confirming the diagnosis, as biopsy in vascular malformations carries hemorrhage risk 1
• Missing radiation history leads to incorrect diagnosis, as radiation-induced telangiectasias require different management than primary telangiectasias 1

When to Refer

• Refer to HHT specialist if ≥2 Curaçao criteria are present for comprehensive organ screening including pulmonary, cerebral, and hepatic arteriovenous malformations 1, 2
• Refer to dermatology if cosmetic treatment is desired for benign telangiectasias, with options including laser therapy, sclerotherapy, or cryotherapy 5, 6, 7