ABSTRACT: Because epidermal integrity decreases with age, eczematous inflammatory dermatoses are more common among older adults than among younger persons. Initial therapy for seborrheic dermatitis consists of mild topical corticosteroids (class IV or weaker) and topical antifungal agents used once or twice a day, either alone or in combination. The goal of therapy for xerosis is to keep the skin moist. Topical corticosteroids are not needed; however, these agents are used to treat a related condition—asteatotic eczema. The cornerstones of treatment of nummular dermatitis are emollients and topical corticosteroids.
Key words: eczema, seborrheic dermatitis, xerosis, asteatotic eczema, nummular dermatitis
Figure 1 – Erythematous patches that are typical of seborrheic dermatitis can be seen on the scalp of this elderly man.
Inflammatory skin disorders are manifestations—for the most part— of the immune response, which wanes with age.1 Thus, it is not surprising that most of these dermatoses are less common in older adults. However, because epidermal integrity also decreases with age, the prevalence of eczematous inflammatory dermatoses is higher among persons older than 60 years.
In this article, I focus on seborrheic dermatitis, xerosis, asteatotic eczema, and nummular dermatitis; I describe and illustrate these conditions, and I discuss their treatment. In a coming issue, I will address stasis dermatitis, irritant contact dermatitis, and allergic contact dermatitis.
Figure 2 – White scales on the face of this man represent seborrheic dermatitis.
Clinical features. Seborrheic dermatitis appears as erythematous plaques or patches topped by white or yellow scale. It most commonly affects the scalp (Figure 1) and the face (Figure 2), particularly the ears (Figure 3), eyebrows, and nasal alae; however, it can also manifest on the chest, anus, and groin, the so-called seborrheic areas. In persons of color, seborrheic dermatitis sometimes appears simply as white, minimally scaly patches on the face underlying the eyebrows. Rarely, seborrheic dermatitis can become secondarily infected with gram-positive organisms (Figure 4).
Figure 3 – Greasy yellowish white scales in and around the ear are characteristic of seborrheic dermatitis.
Prevalence, associated diseases, and causes. The prevalence of seborrheic dermatitis among the general population is estimated to be 1% to 5%; however, simple scaling of the scalp (dandruff) is more common. Seborrheic dermatitis tends to affect men more frequently than women.2 The prevalence also seems to be increased in patients with neurological diseases such as Parkinson disease (35% of patients) and post-stroke neuropathies.3 Other diseases associated with seborrheic dermatitis include epilepsy, congestive heart failure, obesity, and chronic alcoholism. Various factors contribute to seborrheic dermatitis, including the presence of sebaceous glands and sebum, overgrowth of Pityrosporum ovale (Malassezia furfur), stress, low humidity and temperature, and activation of the alternative complement pathway.
Treatment. Initial treatment of seborrheic dermatitis consists of mild topical corticosteroids (class IV or weaker) and topical antifungal agents used once or twice a day, either alone or in combination. Fluocinolone(Drug information on fluocinolone) acetonide 0.01% scalp oil (Derma-Smoothe/FS) is especially helpful in patients who have thick scalp plaques. Corticosteroids in foam preparations have high acceptance among patients with seborrheic dermatitis of the scalp.
Figure 4 – Secondary infection of seborrheic dermatitis, shown here in an elderly woman, is uncommon.
Shampoos with antifungal agents, salicylic acid(Drug information on salicylic acid), tar, selenium(Drug information on selenium) sulfide, corticosteroids, and zinc pyrithione all are helpful in treating seborrheic dermatitis of the scalp. To increase the effectiveness of these shampoos, tell patients to alternate them (eg, antifungal on Monday, zinc on Tuesday, selenium on Wednesday, tar on Thursday, etc).
Topical calcineurin inhibitors (eg, tacrolimus(Drug information on tacrolimus), pimecrolimus(Drug information on pimecrolimus)) can be useful, particularly when rosacea and seborrheic dermatitis overlap. I treat severe seborrheic dermatitis with oral antifungal agents.
Clinical features. Xerosis is common in elderly persons; it is characterized by pruritic, dry, cracked, and fissured skin (Figure 5). Visible xerosis occurs most frequently on the legs. Sometimes the condition is so severe as to overlap with ichthyosis, which manifests with thick, fish scale–like xerotic plaques (Figure 6). It can also occur in association with tinea pedis (Figure 7).
Figure 5 – Xerosis and lichen simplex chronicus are evident on this patient's arm.
Xerotic skin has the appearance of cracked porcelain; the cracks arise from loss of water from the epidermis. Xerosis disrupts the desquamation process; powdery flakes develop and become visible on the surface of the skin. In the winter, when humidity is lower, xerosis tends to be more severe.
Causes. Although xerosis can be considered an inflammatory dermatosis because it is often accompanied by erythema and some inflammation, the condition results in large part from physical changes in the skin that occur with normal aging. The decreased activity of sebaceous and sweat glands in elderly persons is one of the main contributing factors. Decreased skin thickness (ie, thin skin caused by inappropriate or pathological desquamation) and decreased hydration also play key roles in the development of xerosis.
Treatment. The treatment of xerosis involves keeping the skin moist. A home humidifier is helpful, particularly when it is kept in the bedroom. Mild soaps and bath oils can be used when bathing to preserve the natural oils of the skin. Natural emollients of the skin must be replaced after showering. Moisturizers, particularly those with dimethicone 1% (silicone), can be applied to damp skin to seal in the moisture that the skin takes up when exposed to water. Ammonium lactate 12% lotion is also very effective in rehydrating xerotic skin.
In addition, patients should avoid washcloths, rough clothing, and abrasives that can abrade the skin. Topical corticosteroids are not needed to treat xerosis; however, they are used to treat a form of eczema related to it—asteatotic eczema.