ANSWER
The correct answer is discoid lupus (choice “d”); see discussion for further details.
Sarcoidosis (choice “a”) is a worthy item in this differential, since it can be chronic, often affects the face (especially in African-Americans), and frequently defies ready diagnosis. But the biopsy was totally inconsistent with this diagnosis; in a case of sarcoidosis, it instead would have shown noncaseating granulomas, which are characteristic of the condition.
Lichen planus (choice “b”) is likewise worth consideration, since it can present in a similar fashion (although the chronicity of this patient’s lesions would have been atypical). Moreover, lichen planus is almost invariably symptomatic (itch). Biopsy would have shown obliteration of the dermoepidermal junction by an intense lymphocytic infiltrate—findings totally at odds with what was seen.
Polymorphous light eruption (PMLE; choice “c”) is the name given to a variety of photosensitivities that, true to the term polymorphous (or polymorphic), can present in numerous ways—although the lesions on any given patient tend to be monomorphic. These can take the form of vesicles, papules, and even erythema multiforme–like targetoid lesions, most commonly (as expected) on sun-exposed skin. Curiously, though, PMLE seldom affects the face or hands. It can manifest early in a patient’s life, but it would have been “seasonal,” disappearing in winter, and would have revealed a totally different picture on biopsy.
DISCUSSION
This patient suffered needlessly for more than half his life for lack of one simple thing: a correct diagnosis. Truth be known, the patient and his family probably bear some responsibility—but at some point, one of his many providers should have either obtained a punch biopsy or sent him to someone who would do so.
Instead, as is often the case, the emphasis was on treatment: trying one thing after another. The lack of success with these endeavors speaks loudly for the need for a definitive diagnosis. This could only be established one way: with a biopsy.
All the items mentioned in the above differential were legitimately considered. So was the possibility of infection, especially atypical types such as mycobacterial, deep fungal, or those involving other unusual organisms (eg, Nocardia, Actinomycetes). As in this case, tissue can be collected and submitted for culture, but the usual formalin preservative will kill any organism, necessitating prompt processing in saline.
Discoid lupus erythematosus (DLE) can be purely cutaneous (as seen here) or can be a manifestation of more serious systemic lupus. In any case, it is an autoimmune process, made worse by the sun, and can be chronic (though this case is exceptional in that regard).
This patient’s chance of developing systemic lupus erythematosus is slight, at most, since his antinuclear antibody test was negative. But his lifetime risk for another autoimmune disease is high.
TREATMENT
DLE is usually treated successfully with a combination of sun avoidance and a course of oral hydroxychloroquine (200 mg QD to bid, depending on the patient’s body habitus and the severity of the disease). Given the advanced state of this patient’s condition, he received the more frequent dosage, which should yield positive results. However, he will likely be on this regimen for some time.