ACLE

Acute Cutaneous Lupus Erythematosus (ACLE) Study Notes

Key Points

• Definition: ACLE is a subtype of cutaneous lupus erythematosus characterized by transient lesions, often exacerbated by sun exposure.

• Clinical Presentation:

  • Malar Erythema: Also known as ‘butterfly rash’, the most common feature.

  • Lesions are usually transient and may resolve without scarring, though dyspigmentation can result.

  • May occur alongside oral ulcers and is frequently linked with active systemic lupus erythematosus (SLE).

  • Associated with anti-dsDNA antibodies and lupus nephritis.

Epidemiology

• No specific epidemiological data available solely for ACLE.

• SLE is more prevalent in women, particularly during childbearing years, and notably in African-American women who develop the disease earlier.

Pathogenesis

• Genetic and Environmental Factors: Interaction crucial in the development of cutaneous LE, including ACLE.

• Environmental Triggers:

  • Ultraviolet Radiation (UVR): a significant inducer of apoptosis, causing translocation of cellular and nuclear antigens.

  • Increases keratinocyte production of SSA/Ro52 and type I interferons (IFNs).

• Cytokine Production:

  • Proinflammatory cytokines including TNF, IL-1, IFN-γ, HMGB1, and IL-18 are stimulated by UVR.

  • Enhanced IFN secretion occurs due to multiple binding interactions with immune receptors.

• Cascade of Immune Response: Involves dendritic cell activation, IFN release, T cell activation, and chemokine production leading to lichenoid tissue reaction.

Rash Description and Clinical Features

• Malar Erythema:

  • Can present with varying severity from mild erythema to pronounced edema.

  • Associated features can include telangiectasias, erosions, dyspigmentation, and epidermal atrophy.

  

Duration and Location

• Lesion Duration: Ranges from hours to several weeks.

• Common Locations:

  • Primarily affects the face, especially the malar region, while often sparing the nasolabial folds.

  • Can also spread to the hands avoiding the knuckles.

  • Oral ulcerations frequently occur.

• Association with SLE: Active systemic disease often correlates with ACLE.

• Rowell Syndrome: May present with erythema multiforme-like lesions in lupus patients. Rare severe presentations can resemble toxic epidermal necrolysis.

Diagnostic Criteria

• Per 2019 EULAR/ACR classification, acute cutaneous lupus is a clinical criterion with a weight of 2.

• The 2012 SLICC classification recognizes several types of rashes characteristic of lupus as diagnostic criteria.

Diagnosis and Investigations

• Lesional Biopsy:

  • Histopathology: Shows mild interface dermatitis with vacuolization of basal keratinocytes and sparse superficial lymphoid infiltrates.

  • Direct immunofluorescence may reveal granular deposits of IgG and/or IgM in lesions.

  

• Systemic Evaluation: Important to assess if systemic lupus is present, utilizing patient history, physical exams, and specific lab tests (e.g., ANA profile, urinalysis, CBC).

Differential Diagnosis

• Conditions to consider:

  • Rosacea (including corticosteroid-induced)

  • Seborrheic dermatitis

  • Sunburn

  • Drug-induced photosensitivity

  • Dermatomyositis

  • Erysipelas

  • Pemphigus types

  • Various dermatitis forms (atopic, contact)

Treatment/Management

• Topical Therapy: Corticosteroids are pivotal for symptom management.

• Systemic Therapy: Antimalarials like hydroxychloroquine are the gold standard.

• Adjunctive Therapy: Emphasis on sun protection and smoking cessation.

Complications

• Possible complications include:

  • Dyspigmentation.

  • Progression to systemic lupus erythematosus (SLE).

  • In very rare cases, severe reactions resembling toxic epidermal necrolysis can occur.

Additional Notes

• The presence of telangiectasias, erosions, dyspigmentation, and epidermal atrophy aids in differentiating ACLE's malar erythema from other facial rashes.

• Note that the three main types of cutaneous LE (ACLE, SCLE, DLE) can coexist in patients.