VANCOUVER (FRONTLINE MEDICAL NEWS)Atopic dermatitis arising de novo in patients in their 60s or older with no history of the disease poses a diagnostic challenge, and a low threshold for biopsy is warranted, Dr. Thomas Bieber said at the World Congress of Dermatology.

“The diagnosis is not very easy, and if you are not sure what you are facing, I urge you to take biopsies in order to exclude cutaneous T-cell lymphoma before treating the patient with any kind of active compound,” cautioned Dr. Bieber, professor and chair of the department of dermatology and allergy at the University of Bonn (Germany).

Very-late-onset atopic dermatitis and cutaneous T-cell lymphoma (CTCL) may look quite similar clinically. There is but a single exception: Primary CTCL usually doesn’t itch, while pruritus is a prominent feature of atopic dermatitis arising in seniors, he added.

New-onset atopic dermatitis at an advanced age is increasing in prevalence, as is true of atopic dermatitis across the rest of the age spectrum. Dr. Bieber said that statistic is certainly borne out in his own clinical practice, where with the graying of the population he is seeing more cases.

He credited Dr. Ryoji Tanei of Tokyo Metropolitan Geriatric Hospital with doing pioneering work in bringing this particular variant of atopic dermatitis to wider attention ( J. Clin. Med. 2015;4:979-97 ). Roughly 30% of patients with atopic dermatitis in their 60s or older report they never had the disease before. Another 20% had atopic dermatitis in childhood, while it arose in early adulthood in the rest.

Atopic dermatitis arising de novo in seniors is a special form of the disease that characteristically involves the face, neck, and trunk while sparing the flexural areas which are so prominently involved in younger patients. The eczema is often erythrodermic. Older men are affected threefold more often than women.

The disorder is characterized by extraordinarily high serum IgE levels: a mean of 8,000 IU in one series reported by Dr. Tanei.

This very-late-onset form of atopic dermatitis tends not to fade away over time. Dr. Tanei has reported that many affected patients die with the inflammatory skin disease, never outgrowing it.

Very-late-onset atopic dermatitis is often resistant to topical therapies; repeated courses of oral corticosteroids may be required.

The differential diagnosis is quite different than in children, where genetic immunodeficiency syndromes are a real concern. While CTCL is the biggie in the differential diagnosis of very-late-onset atopic dermatitis, other conditions that need to be considered include psoriasis, contact dermatitis, pityriasis rubra pilaris, and pityriasis rosea.

Dr. Bieber is a consultant to and recipient of research grants from numerous pharmaceutical companies having an interest in dermatology.