Cutaneous Sarcoidosis

Cutaneous sarcoidosis is a skin condition that occurs in up to one third of people with sarcoidosis, a disease that causes tiny clusters of inflammatory cells to form in various organs. Because the skin lesions can appear in many different forms, cutaneous sarcoidosis is known as one of the “great imitators” in dermatology.

Table of contents

• What is Cutaneous Sarcoidosis
• Who is Affected
• Possible Causes
• Types of Skin Lesions
• How is it Diagnosed
• Treatment Options

What is Cutaneous Sarcoidosis

Cutaneous sarcoidosis is a condition affecting the skin that is part of a larger disease called sarcoidosis. Sarcoidosis is a disease that can affect almost any organ in the body, though it most commonly affects the lungs. The disease is characterized by the formation of noncaseating granulomas, which are tiny clusters of inflammatory cells that group together^[1].

Skin involvement occurs in 20 to 35 percent of patients with systemic sarcoidosis and may occur even without systemic involvement^[1]. The skin is the second most commonly affected organ after the lungs in people with sarcoidosis, and the condition may be involved in 25 to 30 percent of cases^[6].

Recognition of cutaneous lesions is particularly important because they provide a visible clue to the diagnosis and are an easily accessible source of tissue for examination under a microscope^[1].

Who is Affected

Sarcoidosis occurs worldwide, affecting people of all races, ages, and both sexes^[4]. African Americans and people of Scandinavian descent have a higher incidence of the disease^[4]. The condition mainly affects people between 30 and 50 years of age^[4].

Women have a greater lifetime incidence than men. African Americans have a 2.4 percent lifetime incidence compared to 0.8 percent in Caucasians^[3]. The disease is more prevalent in women, non-smokers, and rural communities^[4].

Possible Causes

The underlying cause of sarcoidosis remains unknown^[1]. No single cause has been identified, but many researchers believe that genetics, environmental factors, and the immune system all play a role in the development of sarcoidosis^[4].

Eleven genetic risk locations have been identified that may make some people more susceptible to developing sarcoidosis. These include specific genetic markers related to the immune system^[4]. First-degree relatives of people with sarcoidosis, particularly identical twins, have a much higher risk of also developing the condition^[4].

Environmental exposures may trigger the disease in people who are genetically susceptible. Exposure to substances such as wood stoves, soil, tree pollen, inorganic particles, insecticides, and silica have been associated with an increased risk of developing sarcoidosis^[4]. Certain bacteria and viruses may also trigger the condition^[4].

Some medications, including certain biological agents used to treat other conditions, have been reported to cause sarcoidosis-like reactions^[4].

Types of Skin Lesions

Because lesions can take on many different appearances, cutaneous sarcoidosis is known as one of the “great imitators” in dermatology^[1]. Involvement may be mild or severe, self-limited or chronic, and limited or widespread^[1].

Skin lesions in sarcoidosis are divided into two main types: nonspecific and specific. Nonspecific lesions occur in association with systemic sarcoidosis, but no granulomas are found when tissue is examined. Specific lesions display noncaseating granulomas when examined under a microscope^[1].

Nonspecific Lesions: Erythema Nodosum

Erythema nodosum is the most common nonspecific skin lesion of sarcoidosis^[1]. It represents a reaction of the immune system to various stimuli. Erythema nodosum usually appears as extremely tender, red nodules under the skin, often on the front of the lower leg^[1].

The onset may be sudden, accompanied by symptoms such as fever, feeling generally unwell, and joint pain. When erythema nodosum appears together with swollen lymph nodes in the chest and joint pain, this combination is called Lofgren’s syndrome, which represents an acute presentation of systemic sarcoidosis^[1].

Specific Lesions

All specific skin lesions show noncaseating granulomas when tissue is examined. Despite having the same appearance under the microscope, the clinical appearance of the lesions can be very different^[1].

The most common types of specific lesions are papules, which are small raised bumps on the skin. They commonly occur on the face but may appear anywhere on the body^[1]. Papules of sarcoidosis may be of various colors, including red, reddish-brown, purple, translucent, or darker than surrounding skin. Most have little surface change and feel firm when touched^[1].

Plaques are larger, raised areas of skin that are another common form of cutaneous sarcoidosis^[1].

Lupus pernio is a chronic form of cutaneous sarcoidosis that typically affects the nose, cheeks, lips, and ears^[1].

Scar sarcoidosis occurs when granulomas form in old scars or sites of previous injury^[1].

Rare forms include hair loss, ulcers, light-colored patches, and changes in skin texture^[1].

How is it Diagnosed

Correctly diagnosing sarcoidosis can be challenging. Unfortunately, no single test can prove the diagnosis^[1]. Patients are diagnosed with sarcoidosis when a compatible clinical or radiologic picture is present, along with evidence of noncaseating granulomas seen under a microscope, and when other potential causes, such as infections, are excluded^[1].

A biopsy is typically used to obtain a sample of skin. A punch or incisional wedge biopsy takes a sample that includes the deeper layer of skin called the dermis^[1]. If noncaseating granulomas are found, additional tests may be necessary to exclude infectious causes^[1].

Your healthcare provider may perform additional tests to check for systemic involvement, including blood tests, chest X-rays, lung function tests, eye exams, and other imaging studies^[11].

Treatment Options

Treatment of cutaneous lesions can be frustrating^[1]. The approach to treatment depends on the severity and extent of skin involvement.

For patients with severe lesions or widespread involvement, the most effective treatment is systemic glucocorticoids, which are medications that suppress the immune system^[1]. A stepwise approach to patient care is appropriate^[9].

For less severe cases, potent topical corticosteroids (such as clobetasol) or repeated injections of triamcinolone directly into the lesions may be used^[9].

Worldwide accepted standard therapies for sarcoidosis include the administration of corticosteroids, antimalarial medications, and methotrexate^[9].

Many people with sarcoidosis never need treatment, as the condition may go away on its own^[5]. Even if you do not have symptoms, you should see your healthcare provider for ongoing monitoring. Your provider will watch for side effects from long-term use of medications and monitor whether the disease is worsening^[17].

If the disease goes into remission, your doctor may carefully stop your medicines. However, you will still need to watch for a flare, which is when symptoms return. If you do have a flare, you may need another round of treatment^[17].

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