Papular Sarcoidosis—The first potential documented case of sarcoidosis was by Hutchinson29 in 1869 in a patient seen in London. The author labeled purple plaques on the index patient’s legs and hands as “livid papillary psoriasis.” In 1889, Besnier30 described a patient with violaceous swellings on the nose, ears, and fingers, which he called “lupus pernio”; his contemporary, Tenneson,31 published a case of lupus pernio and described its histologic profile as comprising epithelioid cells and giant cells. It was not until 1899 that the term sarkoid was used to describe these cutaneous lesions by Boeck,32 who thought they were reminiscent of sarcoma. In 1915, Kuznitsky and Bittorf33 described a patient with cutaneous lesions histologically consistent with Boeck’s sarkoid but additionally with hilar lymphadenopathy and pulmonary infiltrates. Around 1916 or 1917, Schaumann34 described patients with cutaneous lesions and additionally with involvement of pulmonary, osseous, hepatosplenic, and tonsillar tissue. These reports are among the first to recognize the multisystemic nature of sarcoidosis. The first possible case of childhood sarcoidosis might have been reported by Osler35 in the United States in 1898.
In the past century or so, an ongoing effort by researchers has focused on identifying etiologic triggers for sarcoidosis. Microbial agents have been considered in this role, with Mycobacterium and Propionibacterium organisms the most intensively studied; the possibility that foreign material contributes to the formation of granulomas also has been raised.36 Current models of the pathogenesis of sarcoidosis involve an interplay between the immune system in genetically predisposed patients and an infection that leads to a hyperimmune type 1 T–helper cell response that clears the infection but not antigens generated by the microbes and the acute host response, including proteins such as serum amyloid A and vimentin.36,37 These antigens aggregate and serve as a nidus for granuloma formation and maintenance long after infection has resolved.
Cutaneous lesions of sarcoidosis include macules, papules, plaques, and lupus pernio, as well as lesions arising within scars or tattoos, with many less common presentations.7,38 Papular sarcoidosis is common on the face but also can involve the extremities.4,7 Strictly, at least 2 organ systems must be involved to diagnose sarcoidosis, but this is debatable.4,7 Among 41 patients with cutaneous sarcoidosis, 24 (58.5%) had systemic disease; cutaneous lesions were the presenting sign in 87.5% (21/24) of patients.38 Histologic analysis, regardless of the lesion, usually shows noncaseating so-called “naked” granulomas, which have minimal lymphocytic infiltrate associated with the epithelioid histiocytes.38,39 Perifollicular granulomas are possible but unusual.40
Treatment depends on the extent of cutaneous and systemic involvement. Pharmacotherapeutic modalities include topical steroids, immunomodulators, and retinoids; systemic immunomodulators and immunosuppressants; and biologic agents.7 Isolated cutaneous sarcoidosis, particularly the papular variant, usually is associated with acute disease lasting less than 2 years, with resolution of skin lesions.7,38 That said, a recent report suggested that cutaneous sarcoidosis can progress to multisystemic disease as long as 7 years after the initial diagnosis.41
Clinical and Histologic Overlap—Despite this categorization of noninfectious facial granulomatous conditions, each has some clinical and histologic overlap with the others, which must be considered when encountering a granulomatous facial dermatosis. Both GPD and GR tend to present with lesions near the eyes, mouth, and nose, although GR can extend to lateral aspects of the face, below the mandible, and the forehead and has different demographic features.15,20,23 Granulomas in both GPD and GR generally are noncaseating and form in a follicular or perifollicular distribution within the dermis.2,15,23 Lupus miliaris disseminatus faciei and GR share a similar facial distribution in some cases.17,20 Even papular cutaneous sarcoidosis has masqueraded as GR clinically and histologically.4