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A 42-year-old man presents with “multiple bumps” that had been growing on his scalp, the back of the neck, and on preexisting scars (Figure 175-1). These lesions started developing slowly over a period of 1 year. The differential diagnosis of these lesions included cutaneous sarcoidosis, acne keloidalis nuchae, and pseudofolliculitis barbae. A punch biopsy was performed and the diagnosis of sarcoidosis was made.
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Sarcoidosis is a multisystem granulomatous disease most commonly involving the skin, lungs, lymph nodes, liver, and eyes. Patients of African descent are more commonly affected compared to white patients. Diagnosing cutaneous sarcoidosis is critical as 30% of these patients have been found to have systemic involvement. Diverse presentations of cutaneous sarcoidosis have been reported in addition to variants of specific sarcoidosis syndromes.
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- Lupus pernio (cutaneous sarcoidosis).
- Darier-Roussy disease (subcutaneous sarcoidosis).
- Löfgren syndrome (erythema nodosum, hilar adenopathy, fever, arthritis).
- Heerfordt syndrome (parotid gland enlargement, uveitis, fever, cranial nerve palsy).
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- Cutaneous manifestations occur in approximately 25% of systemic sarcoidosis patients.
- The ratio between patients with only cutaneous sarcoid versus multisystem involvement is 1:3.
- Specific cutaneous involvement is seen most commonly in older, female patients of African descent (Figures 175-2 and 175-3).
- Common types are maculopapular, lupus pernio, cutaneous, or subcutaneous nodules, and infiltrative scars.
- Erythema nodosum (EN) occurs in 3% to 34% of patients with sarcoidosis and is the most common associated skin finding (see Chapter 178, Erythema Nodosum).
- Sarcoidosis-related EN is more prevalent in whites, especially Scandinavians. Irish and Puerto Rican females are also affected more often.
- EN occurs between the second and fourth decades of life, more commonly in women.
- Nonspecific lesions of sarcoidosis reported, besides EN, include erythema multiforme, calcinosis cutis, prurigo, and lymphedema. Nail changes can include clubbing, onycholysis, subungual keratosis, and dystrophy, with or without underlying changes in the bone (cysts).
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- Sarcoidosis is a granulomatous disease with involvement of multiple organ systems with an unknown etiology.
- The typical findings in sarcoid lesions are characterized by the presence of circumscribed granulomas of epithelioid cells with little or no caseating necrosis, although fibrinoid necrosis is not uncommon.
- Granulomas are usually in the superficial dermis but may involve the thickness of dermis and extend to the subcutaneous tissue. These granulomas are referred to as “naked” because ...