What is the cause and treatment of a white patch under the eyes?

White Patch Under the Eyes: Diagnosis and Management

Most Likely Diagnosis

The white patch under the eyes is most likely vitiligo, an acquired depigmentation disorder characterized by selective loss of melanocytes resulting in white macules and patches. 1, 2

Diagnostic Approach

Clinical Examination Features to Assess

• Symmetry and distribution: Vitiligo typically presents symmetrically and commonly affects periocular areas, body orifices (mouth, eyes, genitalia), fingers, wrists, axillae, and groins 1
• Surface characteristics: In vitiligo, there is no surface change, no scaling, and usually no redness (occasionally mild inflammation at advancing edges) 1
• Trichrome appearance: Look for a white center with an intermediate pale area around it, which is characteristic 1
• Hair involvement: Check for white eyelashes or depigmented hair within the patches, indicating follicular melanocyte destruction 1
• Mucosal involvement: Examine for depigmentation of oral mucosa, which can be prominent in darkly pigmented individuals 1

Wood's Light Examination

Use Wood's light (handheld UVA device) to delineate areas of pigment loss that may not be visible to the naked eye, especially in pale skin. 1 This is particularly useful for:

• Identifying actively depigmenting areas (appear larger under UV than visible light) 1
• Assessing areas of repigmentation (may appear larger or smaller with UV) 1
• Combined assessment in natural and Wood's light provides the most accurate evaluation 1

Critical Differential Diagnoses to Exclude

While vitiligo is most common, you must exclude malignant lesions, particularly in elderly patients or those with atypical features: 3

• Conjunctival melanoma: Painless, flat or nodular brown lesions on bulbar or palpebral conjunctiva (though typically pigmented, amelanotic variants exist) 3
• Sebaceous carcinoma: May appear as yellowish discoloration of tarsal plate or subconjunctival multilobulated yellow mass 3

Red flags requiring urgent evaluation and biopsy include: 3

• Enlargement of lesion
• Development of blood vessels within the lesion
• Thickening or elevation
• Recurrence in the same location
• Elderly patient with history of multiple excisions

When to Perform Slit-Lamp Biomicroscopy

Perform slit-lamp examination to evaluate location, depth, elevation, and associated findings if there is any concern for conjunctival involvement or atypical features. 3 This is essential to differentiate superficial skin lesions from deeper conjunctival pathology.

Associated Conditions to Screen For

Screen for autoimmune thyroid disease and other autoimmune conditions, as 34% of adults with vitiligo have autoimmune thyroid disease and 32% have a family history of autoimmune disease. 1 Specifically:

• Thyroid function tests (TSH, free T4) 1
• Thyroid autoantibodies 1
• History of other autoimmune conditions (rheumatoid arthritis, diabetes mellitus, alopecia areata) 2

Treatment Options for Vitiligo

General Principles

Treatment should be initiated based on extent, location, and patient distress, as vitiligo can cause severe psychological distress and diminished quality of life. 2

Specific Treatment Modalities

The evidence supports multiple approaches, though specific treatment protocols are beyond the scope of the provided guidelines. Based on the research evidence:

• Topical corticosteroids and immunomodulators are first-line for localized disease 4
• Phototherapy (alone or in combination) is used for patients who do not respond to topical treatment 4
• Systemic therapy and surgical options are available for extensive or refractory cases 4

Common Pitfalls to Avoid

• Do not assume all white patches are benign vitiligo in elderly patients - always consider malignancy and perform appropriate evaluation 3
• Do not overlook the psychological impact - vitiligo causes significant distress and psychiatric morbidity requiring supportive care 2
• Do not forget to screen for thyroid disease - this is present in one-third of adult patients and requires management 1
• Do not confuse pooling of fluorescein stain in areas of corneal thinning with true epithelial staining if performing ocular surface evaluation 1

When to Refer

• Refer to dermatology for definitive diagnosis and treatment planning of vitiligo 1
• Refer to ophthalmology urgently if slit-lamp examination reveals atypical features, conjunctival involvement, or any concern for malignancy 3
• Consider biopsy for atypical features, recurrent lesions, or elderly patients with concerning characteristics 3