Related Experiment Video

Updated: Aug 15, 2026

The Goeckerman Regimen for the Treatment of Moderate to Severe Psoriasis
11:39

The Goeckerman Regimen for the Treatment of Moderate to Severe Psoriasis

Published on: July 11, 2013

Photoallergic contact sensitization to 6-methylcoumarin in poikiloderma of Civatte

Vasanop Vachiramon1, Penpun Wattanakrai

  • 1Division of Dermatology, Department of Internal Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.

Dermatitis : Contact, Atopic, Occupational, Drug
|October 26, 2005
PubMed

A 49-year-old woman presented with asymptomatic progressive erythema, hyperpigmentation, atrophy, and telangiectasia on her neck. The clinical appearance and histopathology of the skin lesion was consistent with poikiloderma of Civatte. Photopatch-testing with our standard photoallergens yielded a positive reaction to 6-methylcoumarin, which was found in the patient's perfume. This report describes the first case in which photoallergic contact sensitization to 6-methylcoumarin may play an important role in the pathogenesis of poikiloderma of Civatte.

More Related Videos

A Mouse Ear Model for Allergic Contact Dermatitis Evaluation08:02

A Mouse Ear Model for Allergic Contact Dermatitis Evaluation

Published on: March 24, 2023

Minimal Erythema Dose (MED) Testing06:24

Minimal Erythema Dose (MED) Testing

Published on: May 28, 2013

Related Concept Videos

Pigmentation01:19

Pigmentation

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...
Skin Cancer01:30

Skin Cancer

Skin cancer is a type of cancer that occurs when there is an abnormal growth of skin cells, usually triggered by damage to the DNA within the skin cells. It is primarily caused by exposure to ultraviolet (UV) radiation from the sun or artificial sources like tanning beds. Skin cancer is the most common type of cancer worldwide, and its incidence continues to rise.
Basal Cell Carcinoma (BCC): BCC is the most common type of skin cancer, accounting for about 80% of cases. It typically develops in...
Allergic Reactions02:06

Allergic Reactions

Overview
Skin Diseases and Disorders01:23

Skin Diseases and Disorders

Skin is the first line of defense and encounters a variety of microbes. Some pathogenic strains are often the cause of a broad range of infections of the skin and other body systems. These conditions can affect people of all ages and may have different causes, including genetic factors, infections, autoimmune reactions, environmental factors, and lifestyle choices.
Gram-positive Staphylococcus spp. and Streptococcus spp. are responsible for many of the most common skin infections. However, many...
Photoreceptors and Plant Responses to Light02:00

Photoreceptors and Plant Responses to Light

Light plays a significant role in regulating the growth and development of plants. In addition to providing energy for photosynthesis, light provides other important cues to regulate a range of developmental and physiological responses in plants.
Photochemical Electrocyclic Reactions: Stereochemistry01:26

Photochemical Electrocyclic Reactions: Stereochemistry

The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation