Experts Say Many Allergic Skin Disorders Are Treatable

Allergic skin disorders, such as urticaria and atopic dermatitis, can cause much discomfort, have an impact on quality of life, and can sometimes cause serious complications. Like other allergic conditions, these disorders can often be effectively treated, according to investigators presenting the latest research at the annual meeting of the American College of Allergy, Asthma and Immunology (ACAAI) in Philadelphia.

Urticaria, also known as hives, affect an estimated 15 percent of the population at some time in their lives. In acute cases, the cause is usually identifiable, stemming from ingestion of a specific food or drug, or from contact with latex or another substance. These cases will usually clear up when the trigger is removed, with or without intervention. However, some individuals have chronic cases of urticaria that persist for months or even years, and can affect both adults and children.

Pediatric Urticaria

"Chronic skin conditions in children have a significant impact on not only the physical well-being of the affected child, but also place emotional, physical and financial demands on the family," said David Weldon, M.D., an assistant professor of internal medicine at Texas A & M University Health Sciences Center in College Station, Texas, and chair of the ACAAI Dermatological Allergy Committee.

Very few studies have addressed quality of life in children with urticaria, but data show that chronic skin conditions may also affect the family dynamics.

"Urticaria in children is infrequent, and seen in only about 3.4 percent of the pediatric population," said Luz Fonacier, M.D., who is head of allergy at Winthrop University Hospital, and an associate professor of clinical medicine at SUNY at Stony Brook in New York. "Only 5 percent of these patients are aged 16 or below."

"In children, the etiology for acute urticaria was seen in about half of patients studied, with infection being the most frequent followed by drug and food hypersensitivity," said Dr. Fonacier.

The cause of chronic urticaria tends to be more elusive. One study found that physical activity was the cause in 53 percent of children studied. Another study was able to establish the cause in slightly under half of the cohort (47 percent), and of this group, 20 percent had physical uritcaria while 18 percent of cases stemmed from an infectious agent.

"Physical urticaria and autoimmune urticaria are the most common causes in children," said Dr. Fonacier.

Parents and even clinicians often overestimate the presence of food allergies as a cause of chronic urticaria. One survey of 220 patients revealed that 31 percent of patients and 20 percent of dermatologists believed that a food allergy was the underlying cause of symptoms, but subsequent serum food allergy testing revealed less than 7 percent were allergic reactions. Another study found that although 52 percent of 54 children were believed by their families to have an allergy to food or a food additive, only 6 percent were confirmed with skin testing and food challenge.

"Children with urticaria may have unnecessary dietary restrictions imposed upon them because of misperceptions by family and health care professionals of foods causing their hives," said Dr. Weldon.

Treating pediatric patients can also be problematic. "It is more challenging to treat urticaria in children because of limited available treatment options for the very young children," said Dr. Fonacier. "Few antihistamines are studied for infants less than 6 months of age."

" The potential for medications to affect learning, development, sedation, cognition, and performance in preschool children is not well studied," said Dr. Fonacier. "Also, the very young child has less ability to communicate and describe their feelings and their behaviors may seem less specific."

Adult Urticaria and Contact Dermatitis

In adults, between 30 percent to 50 percent of chronic urticaria have an autoimmune etiology and anywhere from 50 percent to 70 percent are idiopathic (from an unknown cause).

Antihistamines are the gold standard of treatment, including non-sedating and sedating H1 antagonists. Second line therapy consists of leukotriene antagonists, H2 antagonists, and corticosteroids. Third tier therapies include agents such as cyclosporine, methotrexate and sulfasalazine.

"A recent case series from Johns Hopkins suggests that sulfasalazine treatment is an effective therapy for approximately 75 percent of adult subjects with chronic urticaria that have been inadequately controlled by antihistamines," said Lisa A. Beck, M.D., associate professor of dermatology at the University of Rochester Medical Center in Rochester, N.Y.

Atopic dermatitis is another potentially debilitating condition that can compromise quality of life. Treatment is usually aimed at controlling itching, repairing the skin, and decreasing inflammation when necessary.

"Atopic dermatitis is thought to occur more commonly in subjects with cutaneous barrier defects and the genetic basis for at least some patients may be one of several mutations that leads to complete lack of filaggrin expression in the outer layers of the skin," said Dr. Beck. "Additionally, atopic dermatitis subjects seem to have an inadequate response to cutaneous microbial exposure that may lead to greater colonization, infection and ultimately, chronic inflammation."

Chronic allergic skin disorders are often accompanied by pruritus (itching), which is the most characteristic and distressing symptom occurring in the skin and/or mucus membranes. Itching can be acute in that the desire to scratch is limited, or chronic, where it persists despite conventional therapies. Intractable itching is a condition in which the cause cannot be removed. Not all pruritus accompanies an obvious skin condition. A systemic cause for pruritus without a rash has been found in 10 percent to 50 percent of evaluated patients.

Patient information on allergic diseases including dermatologic disorders is available by calling the ACAAI toll free number at (800) 842-7777 or visiting its Web site at http://www.acaai.org/.

About ACAAI

The American College of Allergy, Asthma and Immunology (ACAAI) is a professional medical organization headquartered in Arlington Heights, Ill., that promotes excellence in the practice of the subspecialty of allergy and immunology. The College, comprising more than 5,000 allergists-immunologists and related health care professionals, fosters a culture of collaboration and congeniality in which its members work together and with others toward the common goals of patient care, education, advocacy and research.

American College of Allergy, Asthma and Immunology (ACAAI)
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