Contact Dermatitis

Con­tact der­mati­tis, also known as a skin rash, occurs for dif­fer­ent reasons.

There are two types of con­tact der­mati­tis: aller­gic con­tact der­mati­tis and irri­tant con­tact dermatitis.

Aller­gic Con­tact Dermatitis

Aller­gic con­tact der­mati­tis occurs when an aller­gen comes in con­tact with pre­vi­ous­ly sen­si­tized skin, result­ing in a rash. Pre­vi­ous expo­sure to the sub­stance is nec­es­sary for this type of con­tact der­mati­tis to occur, but the reac­tion can occur any time after the first expo­sure. This means a sub­stance can become an aller­gen at any time, even if a patient has been in con­tact with that sub­stance for many years. For exam­ple, a patient may sud­den­ly devel­op aller­gic con­tact der­mati­tis on her ear­lobes after wear­ing ear­rings every day for the past five years. Com­mon aller­gens include cos­met­ics, per­son­al hygiene prod­ucts, soaps, per­fumes, fab­rics, and metals.

Irri­tant Con­tact Dermatitis

Irri­tant con­tact der­mati­tis is an inflam­ma­to­ry reac­tion to a sub­stance that results in a skin rash. No pre­vi­ous expo­sure to the sub­stance is nec­es­sary, so the reac­tion can occur with just one expo­sure to an irri­tat­ing sub­stance and con­tin­ue with sub­se­quent expo­sures. For exam­ple, a patient may devel­op irri­tant con­tact der­mati­tis after spilling pes­ti­cide on his skin. Com­mon irri­tants include soaps, cleansers, fab­rics, and occu­pa­tion­al chemicals.

A biop­sy per­formed in a der­ma­tol­ogy office can con­firm the pres­ence of an ongo­ing der­mati­tis, but it can’t iden­ti­fy the causative agent or agents, which is key to pre­vent­ing future reac­tions. To iden­ti­fy these agents, a com­pre­hen­sive patch test is often nec­es­sary; this test should also be per­formed in a der­ma­tol­ogy office.

Our der­ma­tol­ogy depart­ment offers a Patch Test Clin­ic at select loca­tions. Our team of trained pro­fes­sion­als will per­form a com­pre­hen­sive con­tact aller­gy test on cos­met­ic and per­son­al care prod­ucts, cloth­ing, occu­pa­tion­al mate­ri­als, and oth­er sub­stances with which a patient may come in con­tact at both home and work.