Related Experiment Video
Updated: Mar 13, 2026
05:44
Skin Biopsy for Diagnosing Discoid Lupus Erythematosus
Published on: June 10, 2025
1.4K
Two histopathological patterns of postinflammatory hyperpigmentation: epidermal and dermal
Ji-Youn Park1, Ji-Hye Park1, Sang Jin Kim1
1Department of Dermatology, Ajou University School of Medicine, Suwon, Korea.
Journal of Cutaneous Pathology
|October 22, 2016
Summary
Postinflammatory hyperpigmentation (PIH) can be histopathologically classified into epidermal and dermal pigmentation groups. The dermal group shows reduced epidermal pigmentation, offering insights for improved PIH treatment.
Area of Science:
- Dermatology
- Pathology
- Skin Biology
Background:
- Postinflammatory hyperpigmentation (PIH) is a common condition.
- Histopathological features of PIH are not well-characterized.
Purpose of the Study:
- To characterize the histopathological features of PIH.
- To classify PIH into distinct groups based on histopathology.
Main Methods:
- Reviewed medical charts of 21 PIH patients.
- Performed punch biopsies of lesional and perilesional skin.
- Utilized histological stains including hematoxylin-eosin, Fontana-Masson, and immunohistochemistry for various markers (MITF, CD68, c-kit, MMP-2, MMP-9).
Main Results:
- Identified two PIH groups: epidermal (13 cases) and dermal (8 cases) pigmentation.
- Epidermal group showed increased basal pigmentation; dermal group showed upper dermal pigmentation and decreased epidermal pigmentation.
- Dermal group exhibited increased perivascular lymphocytic infiltration, higher CD68 and c-kit expression, and upregulated MMP-2 in lesional skin.
Conclusions:
- PIH can be histopathologically classified into epidermal and dermal pigmentation types.
- The dermal pigmentation group is characterized by decreased epidermal pigmentation.
- Findings provide histopathological insights for enhanced PIH treatment strategies.
Related Concept Videos
01:19Pigmentation
4.8K
The color of the skin is influenced by a number of pigments, including melanin, carotene, and hemoglobin. Recall that melanin is produced by cells called melanocytes, which are found scattered throughout the stratum basale of the epidermis. The melanin is transferred to the keratinocytes via melanosomes.
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...
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...
4.8K
01:19Clinical Applications of Epidermal Stem Cells
3.4K
Epidermal stem cells (EpiSCs) are mainly located at the basal layer of the epidermis. These cells repair minor injuries of the skin and replace dead skin cells. However, EpiSCs’ cannot heal severe wounds such as major burns or those from diabetes or hereditary disorders. In such cases, culturing the epidermal stem cells from the patient is possible and has yielded successful treatment options, such as laboratory-grown skin grafts. These grafts are synthesized using a patient’s own...
3.4K
01:11Papillary Dermis
6.6K
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...
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...
6.6K
01:12Renewal of Skin Epidermal Stem Cells
3.2K
The skin is divided into epidermis, dermis, and hypodermis, the skin's outermost, middle, and inner layers. The human epidermal layer regularly undergoes renewal, where old, dead cells are replaced by new cells. Epidermal stem cells or EpiSCs divide and differentiate to restore the lost cells. For the renewal process, some EpiSCs continuously self-renew. In contrast, few others differentiate into transit-amplifying cells, which later form prickle or spinous cells, followed by granular...
3.2K
01:15Reticular Dermis
5.4K
The papillary and reticular dermis are the two layers of the dermis. They are made of connective tissue with fibers of collagen extending from one to the other, making the border between the two somewhat indistinct. The dermal papillae extending into the epidermis belong to the papillary layer, whereas the dense collagen fiber bundles below belong to the reticular layer.
Reticular Layer
Underlying the papillary layer is the much thicker reticular layer, composed of dense, irregular connective...
Reticular Layer
Underlying the papillary layer is the much thicker reticular layer, composed of dense, irregular connective...
5.4K
01:14Changes in Skin Color: Clinical Perspectives
4.1K
The first thing a clinician sees is the skin, so the examination of the skin should be part of any thorough physical examination. Most skin disorders are relatively benign, but a few, including melanomas, can be fatal if untreated. A couple of the more noticeable disorders, albinism and vitiligo, affect the appearance of the skin and its accessory organs.
Albinism
Albinism is a genetic disorder that affects (completely or partially) the coloring of skin, hair, and eyes. The defect is primarily...
Albinism
Albinism is a genetic disorder that affects (completely or partially) the coloring of skin, hair, and eyes. The defect is primarily...
4.1K