subject: Atopic dermatitis and clinical features [print this page] Atopic dermatitis and clinical features Atopic dermatitis and clinical features
The primary and predominant symptom of atopic dermatitis is itching. This sets up a vicious cycle. Itching leads to scratching, scratching causes lichenification, and lichenification lowers the threshold for itch. Three phases are recognized in atopic dermatitis, namely:
Infantile phase The onset is usually in the third month of life. The child is fair, fat, anxious, with shiny eyes, and glassy expression. The face, particularly the cheeks are the usual affected site. The skin is erythematous and dry with few papulovesicles and scant oozing. The course is marked by remissions and relapses. However, it usually disappears by the age 2 years.
Childhood phase The dermatitis recurs between the ages of 4 and 10 years. At this time it tends to localize in the flexural areas, the antecubital and popliteal fossae, neck, eyelids, and behind the ears. The eruption may become generalized. The features are essentially of erythema, edema, vesiculation, and oozing.
Adolescent and adult phase The lesions are dry, lichenified, hyperpigmented plaques in flexor areas, in addition to eruptions elsewhere in the body.The atopic subject may have stigmata and suffer from complications. A linear transverse fold below the edge of lower eyelids, known as Dennie-Morgan's fold is indicative of atopic diathesis. Thinning of the lateral eyebrows, Hertoghes sign is some time present. Cataract may be associated finding. The opacities are unilateral in about half of the cases, and the anterior cortex is twice as often involved as the posterior cortex. Superimposed infections such as verrucae vulgaris, molluscum contagiosum, and dermatophytosis are common. Staphylococcus aureus dominates the skin flora. It colonizes the eczematous lesions of atopic dermatitis. There is increased susceptibility to generalized herpes simplex infection resulting in Kaposi's varicelliform eruption.
