A 34-year-old man comes to the physician with lesions on his face, scalp, and neck. He has had the lesions for 1 year and they are slowly growing in size and number. There is mild pruritus that worsens with exposure to sunlight. The patient has no fever, arthralgias, or myalgias. He has no other medical problems and takes no medications.
The neck lesion is shown in the photograph below.

Lesions on the face and scalp have a similar appearance. The scalp lesion has hair loss.
Which of the following is the most likely diagnosis?

Question

A 34-year-old man comes to the physician with lesions on his face, scalp, and neck.  He has had the lesions for 1 year and they are slowly growing in size and number.  There is mild pruritus that worsens with exposure to sunlight.  The patient has no fever, arthralgias, or myalgias.  He has no other medical problems and takes no medications.
The neck lesion is shown in the photograph below.

Lesions on the face and scalp have a similar appearance.  The scalp lesion has hair loss.
Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

This patient's photosensitive rash is most consistent with chronic discoid lupus erythematosus (DLE). DLE affects women more commonly than men, and African Americans and Hispanics have a higher predilection for the condition. The morphology of discoid lupus erythematosus is characteristic. The primary lesions (as above) appear as red-to-violaceous, inflamed, scaly, and round (discoid) lesions. With time, increased inflammation may lead to pigment changes with increasingly adherent scaling. Once the lesions heal or burn out, the secondary changes, including an atrophic hypopigmented scarring center with hyperpigmented peripheral borders, evolve in place of the initial lesion. Given the photosensitive nature of this disease, it is most commonly seen on the head/neck and arms. The rash usually extends into hair follicles to cause follicular plugging and hair loss (permanent scarring alopecia). DLE can occur in up to 25% of systemic lupus erythematosus (SLE) patients but can also occur without any other SLE findings. DLE patients, especially those with numerous and generalized lesions, have a 5%-10% risk of eventually developing mild SLE. DLE is usually associated with negative or low-titer anti-nuclear antibodies. However, anti-Ro antibodies are rarely positive. Diagnosis is usually clinical but sometimes may require skin biopsy to distinguish it from other scaly (eg, psoriasis) or keratotic (eg, lichen planus, eczema) skin conditions. DLE treatment includes sunscreen, protective clothing, and topical corticosteroids or calcineurin inhibitor (eg, tacrolimus). Antimalarial agents (eg, hydroxychloroquine) are reserved for lesions refractory to topical therapy. (Choice B) Lichen planus lesions are commonly seen on flexor surfaces of the extremities, particularly the wrists. Lesions are intensely pruritic when they ulcerate. Lichen planus (Choice C) Psoriasis typically presents as erythematous papules and plaques with a silver scale. It does not usually cause hair loss, scarring, or dyspigmentation (hyperpigmented rims). Sunlight (ultraviolet) exposure improves psoriasis but worsens DLE. Antimalarial drugs improve DLE but worsen psoriasis. Psoriasis (Choice D) Subacute cutaneous lupus is a photosensitive rash that typically presents with erythematous and scaly papules or plaques on the neck, upper chest, and arms. It does not cause scars or atrophy of the skin, as seen in this patient. Subacute cutaneous lupus (Choice E) Vitiligo is due to loss of some or all melanocytes in affected skin. It is not photosensitive and presents as depigmented macules and patches. Vitiligo Educational objective: Discoid lupus erythematosus typically presents with photosensitive patches of various sizes that are erythematous and well-defined. The lesions tend to heal with hair loss, skin atrophy, deep scarring, and peripheral hyperpigmentation. Treatment includes sunscreen, protective clothing, and topical corticosteroids or calcineurin inhibitor (eg, tacrolimus). __________ References: Determining risk factors for developing systemic lupus erythematosus in patients with discoid lupus erythematosus. (http://www.ncbi.nlm.nih.gov/pubmed/21910708) Early diagnosis and treatment of discoid lupus erythematosus. (http://www.ncbi.nlm.nih.gov/pubmed/19264946) Treatment of cutaneous lupus. (http://www.ncbi.nlm.nih.gov/pubmed/21503694)

A 34-Year-Old Man Comes to the Physician with Lesions on His