Skin nontumor
Spongiotic, psoriasiform and pustular reaction patterns
Allergic contact dermatitis
Topic Completed: 1 July 2011
Minor changes: 18 March 2020
Copyright: 2002-2020, PathologyOutlines.com, Inc.
PubMed Search: Allergic contact dermatitis [title] skin
Table of Contents
Definition / general | Case reports | Clinical images | Microscopic (histologic) description | Microscopic (histologic) imagesCite this page: Hamodat M. Allergic contact dermatitis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skinnontumorallergiccontact.html. Accessed October 24th, 2020.
Definition / general
- Due to topically applied antigens, such as poison ivy or nickel, which cause delayed hypersensitivity reaction with itching or burning
- Dermatitis occurs at site of contact
- Antigens are initially taken up by Langerhans cells and carried to lymph nodes
- Upon reexposure, cytokines are released, causing endothelial activation and adherence of memory T cells, which release lymphokines, causing spongiotic dermatitis
- May get bacterial superinfection (impetiginization)
Case reports
- 30 year old with exposure to textile dyes (Dermatology Online Journal 7(1):9)
Clinical images
Images hosted on other servers:
Linear demarcation due to textile dyes
Due to hair dye
Microscopic (histologic) description
- Extensive spongiosis, initially acute spongiotic dermatitis, evolving into subacute or chronic spongiotic dermatitis, which then resolves
- May have intraepidermal vesicles, exocytosis, papillary dermal edema or perivascular lymphocytic infiltrates in upper dermis, also numerous eosinophils
Microscopic (histologic) images
Images hosted on other servers:
Various images
Psoriasiform epidermal hyperplasia
with spongiosis and parakeratosis;
superficial perivascular infiltrate of
lymphocytes and eosinophils with exocytosis
