Eczema

This post was updated on January 06, 2020.

A mast cell is a type of white blood cell that is part of the immune system, and it contains many granules that are rich in histamine and several other chemicals. Mast cells are best known for their role in allergic reactions which are initiated by allergens cross-linking high-affinity IgE receptors on their surface. This leads to the release of histamine which typically leads to hives, swelling, hypotension (low blood pressure), bronchospasm with symptom of cough, wheeze and chest tightness, and digestive problems such as diarrhea and vomiting. However, mast cells can cause problems outside of classic allergic reactions as well.

One of the mast cell diseases is mastocytosis, which is characterized by the overproduction of mast cells and CD34+ mast cell precursors. People affected by mastocytosis are susceptible to itching, hives, and anaphylactic shock, caused by the release of histamine from the abundant mast cells. Most cases of mastocytosis are localized to skin, or cutaneous. The most common form of this cutaneous mastocytosis is called urticaria pigmentosa. Urticaria pigmentosa can be diagnosed by identifying dark brown and fixed lesions that forms a hive (or urticates) when scratched. However, urticaria pigmentosa can evolve into systemic mastocytosis which involves the bone marrow and other rare mast cell diseases, such as mast cell leukemia and mast cell sarcoma.

A blood test called a serum tryptase level is the initial screening test for suspected systemic mastocytosis. To confirm the diagnosis a biopsy of the bone marrow or the affected organ to identify an increased numbers of mast cells is needed. There is currently no cure for mastocytosis, but the symptoms are alleviated by a number of medications, such as antihistamines, leukotriene blockers, mast cell stablilizers, corticosteroids, and epinephrine. Other medications that have been used in mastocytosis include proton pump inhibitors to reduce the increased gastric acid production, bronchodilators like Albuterol to reverse bronchoconstriction, calcium channel blockers to reduce mast cell degranulation, and chemotherapy or Gleevec in severe systemic disease.

Another mast cell disorder is mast cell activation syndrome (MCAS) which is characterized by the same symptoms as mastocytosis. In MCAS, however, there is a normal number of mast cells which are defined as “hyperresponsive.” Named as a new diagnosis as recently as 2007, MCAS is often found in patients with Ehlers-Danlos syndrome, postural orthostatic tachycardia syndrome, and idiopathic anaphylaxis. Symptoms can be caused or worsened by triggers such as specific foods and drinks (especially alcohol), temperature extremes, exercise, and emotional stress. Diagnosis of MCAS is often difficult, but laboratory evidence of elevated mast cell mediators such as N-methyl histamine and prostaglandin D2 is helpful, as is a good response to the same drugs used in mastocytosis.

Although rare, mast cell disorders mimic the symptoms of severe allergic reactions and anaphylaxis. Allergy Partners’ board certified Allergist-Immunologists are specialty trained in the diagnosis and treatment of both anaphylaxis and mast cell disorders. Our physicians work collaboratively with area specialists (such as hematologists) as well as tertiary care centers to ensure that patients with mast cell disorders receive the best care possible. Additionally, some of our physicians have particular interest in mast cell disorders. To learn more, visits www.allergypartners.com or contact your trusted Allergy Partners physician.

Dr. Sol Drapkin,

Allergy Partners of Chicago

Atopic dermatitis, also known as atopic eczema, is an inflammatory skin condition leading to itchy, red, swollen and cracked skin. It typically starts in childhood, but up to 40% of patients will continue to have eczema into adulthood. This skin condition can greatly affect patients with itchy skin interfering with sleep and focus on daily activities such as school, sports and work. Breakdown in the skin due to scratching can also lead to secondary skin infections. The reddened and thickened areas, known as lichenification, can also be embarrassing for patients in public.

Atopic dermatitis is a chronic condition that requires daily treatment. Typical treatments include daily hydration and multiple applications of lubrication, as much as 4-5 times a day. Topical steroids, beneficial to help control the inflammation, are also applied but can cause side effects such as thinning of the skin and decreased pigment leading to whitish areas where the steroids were applied. Oral antihistamines, like Benadryl or Claritin, can also be added to help with itching. Atopic dermatitis is a condition that is difficult for many patients to fully control.

Recently, two new treatments have been approved for atopic dermatitis and have shown significant improvement in control of this condition.

1. Eucrisa (crisaborole 2% ointment) has been approved for ages 2 and older for mild to moderate atopic dermatitis. It acts as a phosphodiesterase inhibitor that most likely affects cytokine signals in the inflammatory cascade, although exact mechanisms have not been clearly defined in atopic dermatitis. This medication is applied to involved areas of skin twice a day. Two studies have shown improvement in atopic dermatitis scoring, which resulted in clear to almost clear skin or improvement of 2 categories from baseline.

2. Dupixent (dupilmab) has been approved for patients 18 years and older with moderate to severe atopic dermatitis. This medicine is given as a subcutaneous injection and acts as an interleukin 4 receptor alpha antagonist that blocks the actions of interleukin 4 and 13 which are implicated in allergic diseases such as atopic dermatitis. Three studies showed improvement in atopic dermatitis symptoms ranging from 40 to 60% for patients who were already on typical medical treatment. Studies are currently being done in patients < 18 years old.

These are two new treatments for atopic dermatitis that address the underlying immune mechanisms and hold hope for better control of this disease for patients affected by them.

To learn more about eczema and how best to manage it, visit your trusted Allergy Partners physician.

Atopic dermatitis (eczema) is a chronic inflammatory skin disorder common in patients and families who have allergic diseases. It affects 10-20% of children and 1-3 % of adults. It usually occurs before the age of 5 years old in most patients although it can develop in adulthood in up to 20% of patients. Atopic dermatitis can also be the beginning of the “allergic march” in many patients who later develop asthma, allergic rhinitis, or both.

Atopic dermatitis is diagnosed clinically by the typical presentation of skin lesions. The rash is itchy and red with eczematous areas that are relapsing in nature. Children usually have the rash on their face, neck, wrists, hands, ankles, and feet. Older children and adults have lichenification (rough, scaly skin) and hyperpigmentation in the flexural folds (elbows, knees) of the extremities. For some patients, allergy testing may help identify potential triggers (environmental or food allergies) that, if avoided, could reduce the rash.

Numerous triggers can worsen atopic dermatitis. These include temperature, humidity, irritants, infections (bacterial and viral), food, inhalant and contact allergens and emotional stress. These should be addressed in each patient to maximize treatment of their atopic dermatitis.

Treatment of atopic dermatitis includes restoring a healthy skin barrier and controlling inflammation. Daily hydration (soaking in lukewarm water for 10-20 minutes daily) and judicial use of skin moisturizers (i.e. lotions, creams, balms, etc.) is the first step to improving the skin barrier. Applying moisturizers several times per day is vital. For severe disease, topical steroids can reduce skin inflammation, but care must be taken to limit their use in order to minimize side effects such as thinning of skin, loss of pigmentation, and stretch-mark formation. In addition, steroid-sparing disease modifying ointments are FDA approved for patients >2 years old and can be used daily to control the skin rash. These include tacrolimus (Protopic), pimecrolimus (Elidel), and crisaborole (Eucrisa).

In 2017, the first biologic medicine was approved by the FDA for atopic dermatitis. Dupilumab (Dupixent) is approved for patients 12 years and older for moderate to severe atopic dermatitis, is given every 2 weeks by subcutaneous injection at home, and has shown vast improvement in patients’ symptoms.

Other complementary treatments include antihistamines to help control itching, bleach baths to decrease bacterial skin colonization, supplementation of Vitamin D in deficient patients, and immunotherapy (allergy shots).

Medications that modify the immune system such as cyclosporine, mycophenolate mofetil, azathioprine, methotrexate, interferon gamma, and systemic corticosteroids have been used in severe cases resistant to other treatments but have significant side effects to consider. Phototherapy has been useful in some severe atopic dermatitis patients. Additionally, hospitalization may be needed for intensified treatments (i.e. wet to dry wraps) or addressing other aspects of the disease such as sleep disturbance, psychosocial issues, separation from environmental allergen exposure, and improving adherence to treatment regimen.

Atopic dermatitis is a chronic disease, but with a multi-tiered approach directed by an allergy specialist at Allergy Partners, patients can successfully manage this disease and dramatically reduce its negative impact on their lives.

By Dr. Tracie Overbeck
Allergy Partners of Central Kentucky