Atypical clinical presentation of pigmented purpuric dermatosis

The term pigmented purpuric dermatosis (PPD) is used for a group of mainly asymptomatic, sometimes pruritic dermatoses that are clinically characterized by an eruption of pinpoint purpuric lesions along with yellow, orange, red and/or brown, often patchy pigmented areas. Traditionally five subtypes have been distinguished, but atypical clinical patterns may also occur. Because of the variable clinical spectrum and the similar histopathologic findings, a strict nosological classification is sometimes difficult or even impossible to achieve. We report a case of PPD with atypical clinical features in a young woman, underlining the difficulties in the clinical classification of this spectrum of diseases.     

WHO/EORTC classification of cutaneous lymphomas 2005: histological and molecular aspects

ABSTRACT: The new WHO/EORTC classification for cutaneous lymphomas comprises mature T-cell and natural killer (NK)-cell neoplasms, mature B-cell neoplasms, and immature hematopoietic malignancies. It reflects the unique features of lymphoproliferative diseases of the skin, and at the same time it is as compatible as possible with the concepts underlying the WHO classification for nodal lymphomas and the EORTC classification of cutaneous lymphomas. This article reviews the histological, phenotypical, and molecular genetic features of the various nosological entities included in this new classification. These findings always have to be interpreted in the context of the clinical features and biologic behavior. AIM: To review the histological, phenotypical and molecular genetic features of the various nosological entities of the new WHO/EORTC classification for cutaneous lymphomas. METHODS: Extensive review of the literature cited in Medline and own data of the authors. RESULTS: The WHO/EORTC classification of cutaneous lymphomas comprises mature T-cell and NK-cell neoplasms, mature B-cell neoplasms and immature hematopoietic malignancies. It reflects the unique features of primary cutaneous lymphoproliferative diseases. CONCLUSION: This classification is as much as possible compatible with the concept of the WHO classification for nodal lymphomas and the EORTC classification of cutaneous lymphomas. The histological, phenotypical and molecular genetic features always have to be interpreted in the context of the clinical features and biologic behavior.     

Genotype-phenotype correlation in italian patients with dystrophic epidermolysis bullosa

Dystrophic epidermolysis bullosa (DEB) is a rare skin disorder that is clinically heterogeneous and is transmitted either in dominant (DDEB) or recessive (RDEB) mode. Nevertheless, all variants of DEB are caused by mutations in type VII collagen gene (COL7A1). We report an analysis of COL7A1 mutations in 51 Italian DEB patients, 27 affected with Hallopeau-Siemens RDEB, 19 with non Hallopeau-Siemens RDEB, two with DDEB, two with pretibial RDEB, and one with inversa RDEB. Forty-one mutations were identified, 18 of which are novel. Mutation consequences were analyzed at the mRNA and protein level and genotype-phenotype correlation was determined. Recessive inheritance of a new case of pretibial RDEB was also established. In RDEB patients, six recurrent mutations were identified: 7344G-->A, 425A-->G, 8441-14del21, 4783-1G-->A, 497insA, and G1664A, the last three being found only in Italian patients. Indeed, haplotype analysis supported propagation of ancestral mutated alleles within the Italian population for these particular mutations. Altogether recurrent mutations account for approximately 43% of RDEB alleles in Italian patients and therefore new DEB patients should first be screened for the presence of these mutations.     

Disseminated congenital comedones

A 3-month-old boy with congenital and extensive skin comedones without any other extracutaneous manifestations is reported. This patient does not fit with other reported disorders of congenital or childhood extensive comedones, such as nevus comedonicus, familial dyskeratotic comedones, idiopathic disseminated comedones, childhood flexural comedones, and acne neonatorum.     

Benzoyl peroxide: Percutaneous penetration and metabolic disposition. II. Effect of concentration

The effect of drug concentrations of 2.5%, 5%, and 10% upon the transepidermal penetration of 14C-benzoyl peroxide in a lotion vehicle was assessed in excised human skin and in vivo in the rhesus monkey. In vitro, penetration of benzoyl peroxide was concentration-dependent, both as to rate and to amount, as measured by the hourly recovery of the metabolite, benzoic acid, from the dermal side of the model. In vivo, the higher the concentration of benzoyl peroxide applied, the greater the amount absorbed, as indicated by the urinary excretion of 14C-benzoic acid. Metabolic disposition of benzoyl peroxide, in turn, was unaffected by drug concentration. In all instances, the benzoyl peroxide absorbed was excreted rapidly in urine as benzoic acid; no hippuric acid was detected at any time. We conclude that (1) use of the excised human skin model for this compound can provide useful data in studies of the effects of vehicle and concentration on topical drug delivery, (2) the transepidermal delivery of benzoyl peroxide, but not its metabolic disposition, is concentration-dependent, and (3) the renal clearance of the systemically absorbed drug is so rapid that it precludes passage through the liver--therefore, no systemic toxicity due to drug accumulation can be expected.