Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Introduction to Hypersensitivity and Inflammatory Skin Disorders

By

Julia Benedetti

, MD, Harvard Medical School

Last full review/revision Sep 2020| Content last modified Sep 2020
CLICK HERE FOR THE PROFESSONAL VERSION

The immune system Overview of the Immune System The immune system is designed to defend the body against foreign or dangerous invaders. Such invaders include Microorganisms (commonly called germs, such as bacteria, viruses, and fungi) Parasites... read more plays a vital role in maintaining the health of all the tissues of the body. The immune system reacts to invaders, such as microorganisms, foreign substances, or cancer cells, and triggers inflammation to attack these invaders. Usually the immune system reaction protects the body and aids healing. However, sometimes an immune system reaction is misdirected at healthy tissues and causes intense inflammation and damage. Hypersensitivity (allergic) and inflammatory skin disorders are caused by immune system reactions that involve the skin. These disorders include the following:

Skin can be involved in a variety of immune system reactions, many of which cause rashes. The word "rash" refers to changes in skin color (such as redness), and/or texture (such as bumps or swelling). Many rashes itch, such as those that often develop after an allergic (hypersensitivity) reaction, but some rashes are painful or cause no sensations. Sometimes an immune reaction is triggered by substances a person touches or eats or by a drug a person takes, but many times doctors do not know why the immune system reacts to produce a rash.

NOTE: This is the Consumer Version. DOCTORS: CLICK HERE FOR THE PROFESSONAL VERSION
CLICK HERE FOR THE PROFESSONAL VERSION
Others also read
Test your knowledge
Ichthyosis
Ichthyosis is a form of severe dry skin that causes it to scale (build up excessive dry skin cells) and flake. Ichthyosis ranges in severity from mild to disfiguring, and may be either inherited or acquired. During which of the following time periods does inherited ichthyosis usually first manifest?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
TOP