The Skinny on Autoimmune Skin

Image found here.

Unfortunately, I have had several opportunities to learn more about autoimmune related skin conditions recently, and I've been just itching (sorry) to share some of my newfound knowledge. A discussion about skin needs to begin with a brief anatomy review. Human skin is comprised of three layers. The excellent chart below is from the University of Maryland Medical Center.

epidermis	The epidermis is the thin outer layer of the skin. The epidermis itself is made up of three sub-layers: stratum corneum (horny layer) This layer contains continually shedding, dead keratinocytes (the primary cell type of the epidermis). The keratin, a protein formed from the dead cells, protects the skin from harmful substances. keratinocytes (squamous cells) This layer contains living keratinocytes (squamous cells), which help provide the skin with what it needs to protect the rest of the body. basal layer The basal layer is the inner layer of the epidermis, containing basal cells. Basal cells continually divide, forming new keratinocytes and replacing the old ones that are shed from the skin's surface. The epidermis also contains melanocytes, which are cells that produce melanin(skin pigment).
dermis	The dermis is the middle layer of the skin. The dermis is made up of the following: blood vessels lymph vessels hair follicles sweat glands The dermis is held together by a protein called collagen, made by fibroblasts (skin cells that give the skin its strength and resilience). This layer also contains pain and touch receptors.
subcutis	The subcutis is the deepest layer of skin and is also known as the subcutaneous layer. The subcutis, consisting of a network of collagen and fat cells, helps conserve the body's heat while protecting other organs from injury by acting as a "shock absorber."

There's a lot going on in that thin layer of skin. What seems to be a just a fleshy layer of body wrapping paper is actually the body's largest organ, with a total surface area of about 20 feet. The skin protects the body from infection, helps regulate body temperature, and facilitates our senses of touch, heat, and cold. In its layers are glands that secrete body oils and sweat, and hair follicles.

About two months ago, I developed a healthy crop of some unhealthy looking spots on my skin. I called my doctor's office to schedule an appointment. What do the spots look like? asked the appointment secretary.

Um. I wanted to use medical terminology specific to skin splotches, but for the life of me, I couldn't remember any of those strange words. It's useful to know some of this terminology when reading dermatology literature. Here's an abbreviated list. You can read a much more detailed description in Skin Lesion Nomenclature from the University of Wisconsin found here.

A skin lesion, or patch of abnormal tissue, can be identified in two ways - by a description of the actual lesion, and by the way the lesions are arranged on the skin. Here are just a few of the most commonly used terms.

Lesion descriptive terms:

Macule: a small area of the skin that has a changed color and is perfectly flat.

Papule: a small solid raised lesion

Vesicle: a small raised and clear fluid filled lesion.

Pustule: a vesicle filled with pus.

Lesion patterns:

Annular: in the shape of a ring

Discrete: lesions that remain separate from each other

Clustered: lesions that occur in a group

Confluent: lesions that overlap or run together

Some skin conditions are autoimmune diseases that arise specifically in the skin. You can read more about these conditions, such as alopecia and vitiligo, here. Other skin problems can be caused by autoimmune diseases that affect the body as a whole, such as Sjogren's syndrome, sarcoidosis, and Lupus. You can read my previous post about sarcoidosis and it's skin rash, erythema nodosum, here.

SLE, or systemic lupus erythematosis can cause the skin to develop a malar rash - a red rash over the cheeks and nose often described as a butterfly rash - or discoid rash with raised, reddened disc shaped patches. This Lupus Foundation of America article is a great resource to learn more about SLE, cutaneous lupus erythematosis, and subacute cutaneous erythematosis, all forms of Lupus.

Sjogren's syndrome also can significantly affect skin. According to the Sjogren's Syndrome Handbook edited by Steven Carsons, M.D. and Elaine K. Harris, the most common manifestation of skin problems associated with Sjs is dryness of the skin. The authors recommend strategies such as the use of unscented body creams that do not contain alcohol, humidifying the home environment, limit the use of moisture-robbing soaps, and avoid lengthy showers and baths.

Aside from dryness, Sjs can cause other cutaneous (skin) issues. This info was taken from a very in-depth article about Sjogren's syndrome on the Medifocus Health site: *update 5/16/10 - Medifocus is now not allowing free access to this guidebook. It is available for purchase online* Grr. 


Estimates of the percentage of Sjogren's syndrome patients who experience skin problems range from 10-40%.Cutaneous vasculitis (inflammation of the blood vessels in the skin) is one of the most characteristic extraglandular manifestations of Sjogren's syndrome and is thought to be due to lymphocytic infiltration into the walls of the blood vessels. Typically, small blood vessels are affected more than large ones.

The most common forms of cutaneous vasculitis seen in Sjogren's syndrome patients (typically patients who have anti-Ro and anti-La antibodies) are:

• Palpable or nonpalpable purpura (purple spots on the skin after blood "leaks" underneath; similar to a bruise) which can cause raised, red skin lesions
• Urticarial lesions (hives)
• Erythematosus micropapules - red spots

Patients with cutaneous vasculitis also may develop non-vasculitic lesions including:

• Petechiae - pinpoint dots
• Photosensitive cutaneous lesions - lesions which are sensitive to light (also seen in patients with systemic lupus erythematosus)
• Livedo reticularis - marbled appearance of the skin
• Lichen planus - small itchy pink or purple spots on arm and/or legs

• Thrombocytopenic purpura - purple areas on the skin related to a decrease in blood platelets
• Vitiligo - white patches on skin due to loss of pigmentation

Cutaneous vasculitis (as well as other forms of vasculitis - see below) is considered to be a significant prognostic indicator with the development of lymphoma and mortality. A large 2004 study of 558 Sjogren's syndrome patients diagnosed with cutaneous involvement reported that 58% of the patients had cutaneous vasculitis and showed a higher incidence of:

• Peripheral neuropathy - damage to the nerves that supply the arms and legs characterized by burning, tingling, numbness and pain
• Raynaud's phenomenon - a circulatory disorder caused by insufficient blood supply to the hands and feet
• Renal (kidney) involvement
• Presence of autoimmune markers such as antinuclear antibodies (ANA) and rheumatoid factor
• B-cell lymphoma

Other skin problems that may be experienced by patients with Sjogren's syndrome include:

• Dry skin - affects up to 55% of patients with Sjogren's syndrome (xerosis)
• Itchy skin
• Burning skin - may be experienced in up to 20% of patients with Sjogren's syndrome
• Skin rashes - may be experienced in up to 10% of patients with Sjogren's syndrome
• Raynaud's phenomenon - may appear before the development of symptoms of dry mouth and dry eyes by many years. It is estimated to occur in up to 30% of patients with Sjogren's syndrome and is usually of minor clinical significance.

Treatment of the above conditions can vary and depend on the severity of the condition. Successful management may include the use of topical agents, such as ointments and moisturizers, avoiding UV rays, and use of medications as prescribed by your physician. You can read more about treatment of skin problems related to Sjogren's syndrome here and here.