الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 159 |  |  |
| | | from | 159 | | |
Abstract
Facial pigmentary disorders are one of the most common dermatological complaints and can be more distressing in patients with higher skin phototype. Unfortunately, FHP can cause severe psychological effect on the quality of life of affected individuals.
The purpose of this study was to determine the prevalence and causes of facial hyperpigmentary disorders among patients of Ain Shams University Clinic as well as the dermoscopic characteristics of the different diagnoses.
In our study, we found that most cases of FHP presented to our clinic during the summer months. This seasonal variation was predictable in a country with a hot dry sunny climate like Egypt. Our patients were characterized mainly by type III and IV Fitzpatrick’s skin colors because of our geographical position in the subtropical zone, where people characterized by darker skin complexion due to higher melanin content, higher eumelanin to pheomelanin ratio and more effective distribution of melanin to guard against ultraviolet (UV) radiation.
Most of our patients were in their forties and there was a predominance of the female sex among the participants this might be attributed to the predominance of melasma as the most common cause of FHP in the study. Besides, females are usually more concerned and negatively affected by the facial hyperpigmentary disorders.
Ultraviolet rays, the main stimulus for melanocyte-induced proliferation, act as a precipitating factor for FHP that can explain the high rate of employees among our cases with history of regular sun exposure in the morning and afternoon hours. Other precipitating factors for FHP were also met in our study like the predisposition of OCP to melasma.
Melasma was the most common diagnosis among the studied cases. This was followed by freckles/lentigines and lichen planus pigmentosus. A significant number of seborrheic keratoses, post-inflammatory hyperpigmentation and acanthosis nigricans cases were also encountered in this study.
Melasma appeared clinically as brown and dark brown patches of different pigmentation patterns. This clinical picture resulted in different shades of brown color by dermoscopic examination. Other dermoscopic features included pseudo-pigment-network and telangictatic vessels.
Freckles are also a common cause of FHP that appeared as light tan to brown spots over the cheeks and nose. Our dermoscopic examination of freckles revealed light tan brown color with dermoscopic demarcation, homogenous symmetrical pigment network, exaggerated pseudonetwork and moth eaten border.
Our dermoscopic examination of LPP revealed that the most prominent features included the characteristic gray brown color with pigment deposition sparing the hair follicle leading to exaggeration of pseudo-network.
Seborrheic keratosis (SK) appeared clinically as dark brown sharply demarcated lesions with “stuck on” appearance over cheeks and temporal areas. Dermoscopic examination of SK showed well demarcated brown to dark brown lesions associated with milia-like cysts, comedo like opening, curved lines and moth eaten borders.
Post-inflammatory hyperpigmentation, a common sequel of inflammatory dermatoses, manifested clinically as brown to dark brown macules in the same distribution of the initial inflammatory condition. Dermoscopically, PIH appeared as brownish colored homogenous perifollicular pigment deposition with prominent telangictatic vessels. Gray colored dots were also noticed in most of cases.
Acanthosis nigricans characterized clinically by dark brown diffuse patches with symmetrical distribution over the temporal region that may extend to cheeks. The diagnosis can be confirmed dermoscopically by the presence of well demarcated brown pigmented lesions, pseudonetwork pattern and gray dots.
Riehl’s melanosis presented clinically with symmetrical gray colored patches of diffuse pattern all over the face sparing the nose. Our dermoscopic examination of Riehl’s melanosis revealed pseudonetwork pattern of gray colored pigment deposition with regular lines.
We found that dermoscopy can be considered as a good tool to detect the level of pigmentation either epidermal or dermal. On comparing the dermoscopic findings with the histopathological studies, we found a good and a very good agreement between them in defining the epidermal and dermal pigmentation. However, mixed cases with dermal and epidermal pigment deposition were harder to determine the level of pigmentation by dermoscopy.
Finally, our study established that facial hyperpigmentary disorders are of abundant cosmetic fears causing significant social embarrassment and psychological distress to a lot of patients. It is a common dermatological complaint that every dermatologist faces daily. In our population, most of FHP lesions are produced by or exacerbated by sun exposure especially in summer season. Dermoscopy is a helpful, rapid and non-invasive technique to reach the diagnosis of FHP especially in query cases and to detect the level of pigment deposition.