Related Experiment Video
Updated: Jun 5, 2026

Precision Implementation of Minimal Erythema Dose (MED) Testing to Assess Individual Variation in Human Inflammatory Response
Published on: October 3, 2019
Erythema dyschromicum perstans
Brook E Tlougan1, Mercedes E Gonzalez, Rajni V Mandal
1Department of Dermatology, New York University, New York, NY, USA.
Abstract:
A 39-year-old Hispanic man presented with widespread, symmetric, hyperpigmented, brown-gray-blue, oval-to-circular, discrete and coalescing patches on the upper extremities, trunk, neck and face, many with an associated annular erythematous border. Histopathologic features showed an interface dermatitis, thin lichenoid and superficial perivascular infiltrates, and dermal melanophages. These changes were consistent with a diagnosis of erythema dyschromicum perstans (EDP). The etiology of EDP is unknown, but many associations have been described. The rim of erythema that appears during the inflammatory phase of the disorder distinguishes it from other disorders of hyperpigmentation. There is no consistently effective treatment for EDP. We highlight the use of narrow-band UV B phototherapy in the treatment of this disorder, which has shown good success in our patient thus far.
Related Concept Videos
Changes in Skin Color: Clinical Perspectives
Albinism
Albinism is a genetic disorder that affects (completely or partially) the coloring of skin, hair, and eyes. The defect is primarily...
Skin Diseases and Disorders
Gram-positive Staphylococcus spp. and Streptococcus spp. are responsible for many of the most common skin infections. However, many...
Skin Cancer
Basal Cell Carcinoma (BCC): BCC is the most common type of skin cancer, accounting for about 80% of cases. It typically develops in...
Pigmentation
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
Endocarditis II: Clinical Features of Infective Endocarditis
Papillary Dermis
The dermis might be considered the "core" of the integumentary system, as distinct from the epidermis and hypodermis. It contains blood and lymph vessels, nerves, and other structures, such as hair follicles and sweat glands. The dermis is made of two layers of connective tissue that comprise an interconnected mesh of elastin and collagenous fibers, produced by fibroblasts.
Papillary Layer
The papillary layer is made of loose, areolar connective tissue, which means the collagen and...
