Dermatology MCQ - Infiltrative and Neoplastic Disorders - Jessner lymphocytic infiltrate

A 40-year-old woman presents with recurrent, annular, erythematous plaques on her face and upper back. The lesions are non-scaly and non-pruritic. They resolve without scarring over several weeks, only to reappear in the same locations. A biopsy reveals a dense, superficial, and deep perivascular lymphocytic infiltrate without significant epidermotropism, interface change, or follicular involvement. Direct immunofluorescence is negative. What is the most likely diagnosis?

A. Discoid Lupus Erythematosus (DLE)
B. Subacute Cutaneous Lupus Erythematosus (SCLE)
C. Polymorphous Light Eruption (PMLE)
D. Jessner's Lymphocytic Infiltrate of the Skin
E. Cutaneous T-cell Lymphoma

Correct Answer: D. Jessner's Lymphocytic Infiltrate of the Skin

Answer and Explanation

The correct answer is D. This question describes the classic presentation of Jessner's lymphocytic infiltrate. The key clues are the recurrent, annular, non-scaly plaques on sun-exposed skin, the lack of symptoms (non-pruritic), and the characteristic histology showing a dense, primarily perivascular lymphocytic infiltrate that is "bland" – meaning it lacks the specific features of its mimics (e.g., no interface dermatitis, no follicular plugging, no mucin deposition). The negative direct immunofluorescence helps rule out lupus erythematosus.

Why the Other Options are Incorrect:

• A. Discoid Lupus Erythematosus (DLE): DLE lesions are typically scaly, atrophic, and cause scarring and permanent hair loss if they involve hair follicles. Histology shows interface dermatitis, follicular plugging, and basement membrane thickening.

• B. Subacute Cutaneous Lupus Erythematosus (SCLE): SCLE presents with annular or psoriasiform plaques that are scaly. Histology shows prominent vacuolar interface dermatitis, and patients often have positive anti-Ro/SSA antibodies.

• C. Polymorphous Light Eruption (PMLE): PMLE is intensely pruritic and occurs within hours to days of sun exposure. While it can be polymorphous, the lesions are typically papules or vesicles and are directly provoked by sunlight, unlike the more persistent and recurrent plaques of Jessner's.

• E. Cutaneous T-cell Lymphoma: This would typically show significant epidermotropism (lymphocytes invading the epidermis) and lymphoid atypia on histology, which are absent in this case.

Additional High-Yield Information for Exams:

• Histopathology: The histology is characterized by a "boring," dense, well-circumscribed superficial and deep perivascular and periadnexal lymphocytic infiltrate. The key is the absence of specific findings:

  • No significant interface change (no hydropic degeneration of the basal layer).

  • No follicular involvement or plugging.

  • No increase in dermal mucin.

  • The lymphocytes are small and mature without atypia.

• Differential Diagnosis: This is a classic "wastebasket" diagnosis of exclusion. The main differentials are:

  • Lupus Erythematosus (especially DLE and SCLE): Differentiated by scale, atrophy, scarring, and specific histologic/immunologic findings.

  • Polymorphous Light Eruption (PMLE): Differentiated by intense pruritus and direct relationship to sun exposure.

  • Reticular Erythematous Mucinosis (REM): A closely related or identical condition characterized by mucin deposition in the dermis on histology.

• Associated Conditions & Prognosis:

  • Relationship to other diseases: There is significant debate over whether Jessner's is a distinct entity or a forme fruste of lupus or REM. Many experts now believe it falls within the spectrum of lupus.

  • Prognosis: The condition is chronic and recurrent but is benign. It causes no systemic involvement.

• Management & Rationale:

  • Rationale: Management is aimed at controlling outbreaks, as there is no cure. Sun protection is a cornerstone.

  • First-line: Strict sun protection (sunscreen, protective clothing).

  • First-line Medical Therapy: Topical corticosteroids can be used for individual lesions. For more widespread disease, hydroxychloroquine is often very effective and is a first-line systemic agent.

  • Other Options: Intralesional corticosteroid injections, thalidomide, or low-dose methotrexate can be considered for refractory cases.