Inflammatory Dermatosis

All students of dermatology, regardless of training level, need a conceptual framework for understanding and organizing thousands of dermatologic conditions. Broadly, the etiology of dermatologic conditions can be split into inflammatory, neoplastic, and other. We aim to highlight important inflammatory dermatologic conditions in the Inflammatory Dermatosis Spotlight.

Atopic Dermatitis

As we enter winter, we will focus on an important and common inflammatory dermatosis that can be affected by a change in weather: atopic dermatitis (AD).

Affecting 20-30% of children and 2-10% of adults, AD is a complex disease with the hallmark of an impaired epidermal barrier. Genetic, environmental, and immune influences contribute to the development of AD.

Figure 1: Atopic dermatitis involving the extensor surface of the cheeks of an infant. Notice the serous drainage. (image courtesy Bolognia 4th Edition)

Presentation

AD’s clinical appearance typically varies based on the age of presentation. Infants typically present with poorly defined, erythematous to lichenified patches on the extensor surfaces of the cheeks, arms, and lower extremities and classically spares the folds on the diaper area.

Figure 2: Characteristic flexural involvement of the popliteal fossa. Note the poorly defined borders. (image courtesy Bolognia 4th Edition)

As the patient’s age, the distribution often changes to involve the flexural surfaces of the arms (antecubital fossa) and legs (popliteal fossa), amongst other areas. Pay attention to other atopic sequelae - sparing of the nasal tip, Dennie-Morgan lines (lichenification of the lower eyelids), the transverse nasal crease, and follicular prominence on the trunk- to help aid in your diagnosis. In older adults, the distribution is less characteristic, and regional eczema variants may be the only sign of AD. These include eyelid, hand, and nipple eczema.

Figure 3: Lichenified scaly thin plaques on the dorsal foot. (image courtesy Bolognia 4th Edition)

Fissuring of the skin with the appearance of yellow crusting can be an indicator of the so-called “infected” AD. We know that those with AD have a much higher concentration of Staphylococcus aureus bacteria on their skin compared to normal controls. We also know that higher concentrations of staph in AD skin can drive flares. Therefore it is important to address this aspect in stubborn or refractory AD. Although there is a lack of data proving oral antibiotic therapy makes a long-term difference in the course of AD, treatment of the “infected” AD patient with oral antibiotics is common amongst dermatologists worldwide.

Figure 4: Characteristic involvement of the AC fossae with surrounding lichenification. (image courtesy Bolognia 4th Edition)

Treatment and Management

Caring for AD during the colder months maintains the same approach to other times of the year with a few key differences. One should always focus on maintaining the health of the skin's barrier. That starts with lukewarm baths/showers, decreasing the staph count with bleach baths/spritzers, ceramide containing creams, or bland petrolatum-based ointments for moisturizing and judicious use of prescribed topical steroids when needed for flares.

Winter-specific tips for managing AD:
A humidifier can go a long way. In addition to the dry air that accompanies winter, turning on the heat in our homes creates a dry environment. Be sure to clean your humidifier.
Opt for breathable, cotton clothing. Wool is certainly a warm clothing option however it has been known to irritate sensitive, AD skin.
Bundle up when outside but remove the layers and let the skin breathe whenever possible.
Don't forget wet wraps! Dampen a long sleeve/pant/onesie with warm water and place it on the skin on top of your moisturizer or prescribed topical steroid. Place a second, dry, and breathable layer of clothing/pajamas on top of the wet layer. This helps calm the skin, increase penetration of moisturizers, and topical therapy. You can leave them on for several hours or overnight.

About this Series

Our mission at Derm for Primary Care is to provide the most up-to-date Dermatology information for healthcare providers. Here is a sneak peek at upcoming articles in the Inflammatory Dermatosis Spotlight series - Psoriasis, Urticaria, Pityriasis Rosea, and more.

Want to learn more? Check out the Atopic Dermatitis course: https://www.dermforprimarycare.com/course-details/2/Atopic-Dermatitis/