Q1: What diagnoses would be consistent with the results of the skin biopsy?

The biopsy findings in this patient are not specific for one disease entity, but may be found in lupus erythematosus, dermatomyositis, as well as some cutaneous drug reactions, and in acute graft versus host disease. Given his constellation of features, as well as his normal neuromuscular examination, muscle enzymes and electromyography results, and the uncommon frequency of cutaneous reactions to prednisone or cimetidine, a clinical diagnosis of lupus erythematosus was made.

Q2: What are the cutaneous lesions of lupus erythematous?

Lupus erythematosus may be limited to the skin or may exist as part of a multisystem disease, systemic lupus erythematosus (SLE). Chronic cutaneous lupus erythematosus lesions include discoid lesions, lupus panniculitis, or hypertrophic (verrucous) lupus erythematosus. The two most common types of subacute cutaneous lupus erythematosus are the psoriasiform (papulosquamous) and annular variants. Approximately 70% of these individuals have the anti-Ro (SS-A) antibody.1 Cutaneous lesions seen in acute lupus include malar erythema, photosensitivity, papular palmar erythema, periungual erythema, Raynaud's phenomenon, diffuse hair loss (telogen effluvium), urticarial vasculitis, leukocytoclastic vasculitis, and bullous lesions. The frequency of systemic involvement is related to the subtype of cutaneous lupus erythematosus and is more common in acute lupus erythematosus (100% SLE), than in subacute lupus erythematosus (50%), and chronic lupus erythematosus (5%–10%)

(3) Does he meet criteria for the diagnosis of SLE?

According to the 1997 criteria by the American College of Rheumatology,2 a diagnosis of SLE can be made when four of the 11 criteria are fulfilled (box 2). Our patient initially met four of the criteria.

Q4: How common is SLE in patients of this age, race, and gender?

SLE is more common in females, who are afflicted almost four times as often as men. Black women are three times more likely to develop SLE than white women, while black men develop SLE 1.5 times more often than white men.3 Although SLE is much more common in younger individuals, approximately 10% of patients are diagnosed when older than 60.4

Q5: As the patient was at risk for HIV infection, what dermatological manifestations of HIV should be considered?

As the patient had been recently tested for HIV and was negative, it would be unlikely that his findings were caused by advanced HIV disease. Patients with acute HIV infection might experience an acute retroviral syndrome, which consists of fever, sweats, arthralgias, myalgias, lymphadenopathy, headache, and a maculopapular eruption on the trunk, face, and upper extremities. An enanthema is also frequently present. The clinical and histological appearance of these lesions are not easily confused with the patient's lesions.

Discussion

There are a variety of cutaneous manifestations of lupus erythematosus. The type of lesion may help predict a patient's course. Our patient's cutaneous lesions were most consistent with subacute cutaneous lupus erythematosus despite the negative anti-Ro antibodies. Originally described in a cohort of 27 patients by Sontheimer and Gilliam in 1979,5 subacute cutaneous lupus erythematosus was found to be associated with alopecia (59%), photosensitivity (52%), mucus membrane ulcers (37%), and facial telangiectasias (30%). Livedo reticularis, periungual telangiectasias, discoid lesions, vasculitis, and sclerosis were each found in less than 25% of their patients. Arthritis or arthralgia (74%), fever or malaise (37%), and myalgia (22%) were the most common systemic manifestations of subacute cutaneous lupus erythematosus. Although central nervous system and renal disease were seen in 19% and 11% respectively, the frequency and severity of involvement is less than in acute lupus. Sixty three per cent of their patients had an antinuclear antibody titre of greater than or equal to 1:160, 59% had an erythrocyte sedimentation rate of greater than 30 mm/hour, 20% had a positive rheumatoid factor, while only 37% were found to have a positive antidouble stranded DNA antibody test. This contrasts to acute SLE, where the antinuclear antibody is positive in greater than 95% of cases, and the antidouble stranded DNA antibody is positive in 60% to 80% of cases.6

Although approximately 70% of subacute cutaneous lupus erythematosus patients will be found to possess the anti-Ro antibody, our patient was found to be anti-Ro negative. Our patient could be part of a subset of patients with subacute cutaneous lupus erythematosus that do not posses the anti-Ro antibody. Alternatively, titres may fluctuate and perhaps with time his anti-Ro antibody will become detectable.

Our patient was initially treated with 60 mg of prednisone daily and 200 mg of hydroxychloroquine twice daily. Within 72 hours, his systemic manifestations were greatly improved. Over the ensuing three months, his skin lesions completely resolved. Interestingly, as the prednisone dose was slowly tapered, he developed oral ulcers approximately three weeks after his discharge from the hospital.

Final diagnosis

Subacute cutaneous lupus erythematosus.