From the face, we will now move to a discussion of the eyelids. The eyelid skin is some of the most interesting on the body. It moves constantly as the eyes open and close; thus, it must possess unique mechanical properties. It must be thin enough for rapid movement, yet strong enough to protect the tender eye tissues. Eyelid tissue shows the state of health and age of an individual more rapidly than any other skin of the body. When others comment on a tired appearance, they are usually assessing the appearance of the eyes and the eyelid tissue. When others comment on a sickly appearance, they are also assessing the appearance of the eyes and the eyelid tissue. The eyelid skin appears to age quickly resulting in the presence of redundant upper eyelid tissue and lower eyelid bags. The redundant upper eyelid tissue is due to loss of facial fat, cumulative collagen loss in the eyelid skin from UV exposure, and the effect of gravity pulling down the upper eyelid skin. Lower eyelid bags are also due to the effect UV damage and gravity, but edema or swelling may also contribute. This edema may be due to retained body fluids or the release of histamine from inhaled allergens. All of these factors contribute to the complexity of the eyelid skin.
Anatomy and Physiology
The eyelids are indeed composed of unique skin. It is the thinnest skin on the body, accounting for the eyelids as the most common site of irritant contact dermatitis and allergic contact dermatitis, either from products that are directly applied to the eyelids or from products transferred to the eyelids by the hands. The eyelid skin also has a paucity of sebaceous glands, making it a common area of skin dryness. While there are no hairs on the eyelids themselves, the eyelashes form an interesting transition between the keratinized eyelid skin and the cartilage of the tarsal plate giving structure to the edge of the eyelid. Tearing from the eye impacts the skin of the eyelid, since wetting and drying of the eyelid tissues can predispose to dermatitis.
The eyelids are also a common source of symptoms induced by allergies. These symptoms can be itching, stinging, and/or burning. Most persons with these symptoms respond by vigorously rubbing the eyelids. This can cause mechanical damage to the eyelid skin, from minor trauma resulting in sloughing of portions of the protective stratum corneum to major trauma resulting in small tears in the skin. Most of the skin on the body responds by thickening or callousing when rubbed. Eyelid skin will also thicken, but this predisposes to decreased functioning and worsening of the symptoms.
Eyelids are also a common site for cosmetic adornment. There are more individual colored cosmetics for the eyelid area than any other body area to include mascara, eyeliner, eye shadow, and eyebrow pencil. These cosmetics and the products used to remove them can be a source of both allergic and irritant contact dermatitis, the next topic of discussion.
Common Dermatologic Disease Considerations
As mentioned previously, the eyelid skin is the most common body site afflicted with irritant and allergic contact dermatitis. Some of this predisposition is due to the thinness of the eyelid skin, but the transitional nature of the tissue is also important. The eyelid bridges the transitional area between the well-keratinized skin of the face and the moist tissue of the conjunctiva that lines the inner eyelid and the eyeball. The moisture from tearing wets the eyelid skin and enhances irritant and allergen penetration. It can also help dissolve any allergen or irritant, possibly enhancing the adverse reaction. The eyes are also uniquely designed to sense substances that might cause vision damage, and thus the eyelids have a heightened immune response. Swelling induced by topical, inhaled, or ingested allergens are frequently seen initially in the eyelids. The thin nature of the skin also allows the swelling, due to tissue edema, to appear more dramatic than on other body areas where the skin is thicker and less mobile.
In addition to irritant and allergic contact dermatitis involving the eyelid skin, there are also eyelid diseases involving the eyelid sebaceous glands found at the base of the eyelash follicular unit. This condition is basically acne of the eyelashes and is found both in adolescents and the elderly. It is treated with oral antibiotics, much like traditional facial acne, but superb eyelid hygiene is necessary to prevent recurrence and the avoidance of oily substances in the eye area that might block the sebaceous gland orifice is mandatory.
A type of dandruff, known as seborrheic blepharitis, can also affect the eyelids. This represents the eyelash equivalent of the seborrheic dermatitis, mentioned earlier, that can affect primarily the scalp and sometimes the folds of the face, such as the skin around the nose and mouth. Seborrheic blepharitis is also caused by fungus; thus, proper eyelash hygiene is the key to control. Most individuals with scaling in the eyelash area will also present with facial and scalp scaling as well, thus necessitating treatment of the entire scalp and face.
The eyelid skin is also uniquely affected by the immune status of the individual. Most persons with inhaled allergies to pollen, fragrance, dust, etc. will complain not only of a runny nose, but also of itchy eyes. The eyelids and the nose both represent areas possessing transitional skin bridging the wet mucosa with the traditional dry keratinized skin. Since the wet mucosa is devoid of a skin barrier to allergens and infection, the immune system is particularly fortified in these locations. For this reason, hyperimmune states that affect the overall body skin are keenly present in the eyelid area. The most common of these conditions is known as atopic dermatitis. Atopic dermatitis is a combination of dry skin, asthma, and hay fever. Thus, these individuals have chronic itchy skin, problems breathing, and bad inhaled allergies. One of the most common sites for this condition to manifest is the eyelid. These atopic persons have chronically itchy eyelids that become red, swollen, and tender. They represent a unique population of sensitive eyelid persons that have problems with many eye area cosmetics and skin care products. Treatment of these individuals usually involves the use of high-potency topical corticosteroids and oral antihistamines.
By far the most common dermatologic disease to afflict the eyelid is eczema, more commonly known as bad dry skin. Since the eyelid is relatively poor in oil glands, dry
eyelid skin is frequently seen due to over-aggressive removal of lipids. This may be due to the use of a strong cleanser or products designed to solubulize oil-based waterproof cosmetics, such as mascara and eyeliner. Anything that damages the intercellular lipids or the corneocytes will result in eyelid eczema. Thus, eyelid hygiene must achieve a careful balance between the removal of excess sebum and old cosmetics to prevent eyelash infections and seborrheic blepharitis, while preventing damage to the intercellular lipids and ensuing eyelid eczema.
Hygiene Needs
Cleansing of the eyelid tissue is indeed a delicate task. Typically, the skin should be handled very gently, due to its thin nature, and cleansing should remove excess sebum while preserving the intercellular lipids. If more aggressive cleansing is required, an appropriate moisturizer must be selected that will provide an environment for healing while the intercellular lipids are resynthesized. The typical cleanser used in the eye area by dermatologists is baby shampoo. This non-stinging shampoo formula allows cleansing of the eyelashes to prevent seborrheic blepharitis, while minimizing further eyelid irritation. Typically, the cleanser is applied with the fingertips and not a washcloth or other cleansing implement, since the fingers can easily sense if too much pressure or force is being used to clean the thin eyelid tissue. Most of the diseases of the eyelid and the eye itself are related to poor eye area hygiene and the onset of infection. Thus, appropriate eyelid hygiene is medically and cosmetically important.
Skin Care Needs
After maintaining good eyelid hygiene through proper cleansing, the issues of moisturization and sun protection must be addressed. These are the skin care needs of the eyelid skin. The recurring theme throughout this discussion of the eyelid has been the unique thinness of the skin. This consideration becomes extremely important when formulating eyelid moisturizers and sunscreens. Any eyelid moisturizer selected must spread easily to prevent bruising or tearing. Thus, highly lubricious emollient formulations are best. They should occlude the eyelid skin enough to allow the skin barrier to repair, but should not be too oily such that they interfere with vision if accidentally introduced into the eye.
The thinness of the eyelid skin also makes the use of sunscreens important. UVA radiation can easily penetrate to the dermis of the thin eyelid skin, causing premature wrinkling. The eyelids are also a common site for UVB-induced sunburn. This makes UVA and UVB broad spectrum sun protection vital, a topic more fully discussed in Chapter 9. It should come as no surprise that most men and women notice aging first in the upper and lower eyelid tissue. This thin skin quickly looses elasticity from photodamage, which can be exaggerated by familial tendencies toward eyelid skin laxity, a condition known as blepharochalasis. Eyelid sunscreens must be carefully formulated to avoid allergic and irritant contact dermatitis, stinging, and burning should the product enter the eye, and limited photoprotection. In addition to sunscreens, excellent eyelid skin protection can obtained through the use of sunglasses and hats.