Lichen aureus: A localized persistent form of pigmented purpuric dermatitis

Localized persistent pigmented macules and plaques due to a chronic form of pigmented purpuric dermatitis are described in forty-two patients. The designation 'lichen aureus' for this eruption can be justified because of the striking yellowish or bronze-like colour assumed by many of the lesions. The lower legs were the commonest sites but other body regions can be affected also. Histologically lichen aureus differs from other pigmented purpuric dermatoses in the density of the lichenoid tissue reaction and the marked accumulation of pigment-containing macrophages. Recently developed endothelial cell markers have been studied in selected cases.     

Unusual case of pemphigus vulgaris mimicking localized pustular psoriasis of the hands and feet

We report a case of a 70-year-old man with a history of chronic plaque psoriasis presenting with new-onset vesiculopustules of the hands and feet. Hematoxylin and eosin stain as well as direct and indirect immunofluorescence were all consistent with a diagnosis of pemphigus vulgaris. Unusual presentations of pemphigus vulgaris have been reported in the literature. Our case easily could have been clinically misdiagnosed as pustular psoriasis.     

Multiple pigmented trichoblastomas and syringocystadenoma papilliferum in naevus sebaceous mimicking a malignant melanoma: a clinical dermoscopic-pathological case study

We report a case of three distinct adnexal neoplasms associated with a naevus sebaceous of the scalp: a nodular pigmented trichoblastoma, a smaller flat pigmented trichoblastoma and a syringocystadenoma papilliferum, and discuss the clinical and histological features of these neoplasms. The clinical manifestation was suggestive of malignant melanoma, a feature that has never been reported before. For the first time in the literature we describe the case also by means of a noninvasive analysis, i.e. epiluminescence microscopy. In our experience, epiluminescence microscopy does not appear to be more diagnostically accurate than simple clinical examination when diagnosing lesions of the scalp, contrary to other regions.     

Severe bullous fixed drug eruption due to metronidazole mimicking a localized form of toxic epidermal necrolysis

A 55-year-old diabetic male who had severe bullous fixed drug eruption mimicking a localized form of toxic epidermal necrolysis 8 hours after taking metronidazole is presented.     

Patterned disorders in dermatology

The skin gives us an opportunity to study pathologies unapparent in other systems such as patterned disorders. Among the best-identified patterns of skin disorders are the well-known lines of Blaschko, but other types of skin-patterned lesions have also been recognized. This short review will describe and discuss these different patterns and their pathophysiologic mechanisms, such as somatic mosaicism and X-chromosome associated mosaicism. Cutaneous patterned disorders are thought to be associated usually with inherited diseases per se, but in fact they are also reported in so-called acquired diseases. These cases suggest the existence of an underlying defect in a gene closely associated with the disease pathogenesis. The study of these acquired patterned disorders in the future may help us to understand the biologic foundations and pathogenesis of common human diseases.