Erythema infectiosum following generalized petechial eruption induced by human parvovirus B19.

Parvovirus B19 is a DNA virus responsible for a wide spectrum of clinical illnesses. Among dermatological manifestations, the most common is erythema infectiosum, also known as the fifth disease. In 1990 Harms et al first described a papular-purpuric gloves and socks syndrome (PPGSS) due to parvovirus B19. It is an acute acral dermatosis characterized by an eruption of petechiae and small purpuric papules affecting the hands and feet in a gloves-and-socks distribution. Recently it was observed that PPGSS may be associated with involvement of the peri-oral region and the chin (acropetechial syndrome) and other sites provoking unusual presentation of the rash. We describe a patient with an acral purpura with the features of the "acropetechial syndrome" involving the buttocks, genital and axillary regions who subsequently developed a maculopapular eruption with the characteristics of the fifth disease. Parvovirus B19 DNA was detected by polymerase chain reaction (PCR) both in skin vasculitic lesions and in the serum during the petechial eruption, before the onset of antibodies. The immune response coincided with the development of the exanthem, suggesting a direct role of parvovirus B19 in the pathogenesis of endothelial cell injury.

Tolerance to calcitriol and tacalcitol in three patients with allergic contact dermatitis to calcipotriol.

We describe 3 cases of psoriatic patients who developed a severe eczematous eruption after the use of calcipotriol ointment. For all of them, the dermatitis recovered after the suspension of the calcipotriol ointment and topical application of corticosteroids. We performed patch tests with the standard series of SIDAPA (Italian Society of Environmental, Occupational and Allergological Dermatology), with an integrative series of vehicles and preservatives, with the commercial ointment containing calcipotriol, with its excipients and, finally, with a series of diluted calcipotriol in isopropanol and petrolatum. They all revealed a strong allergic reaction to calcipotriol and also to its dilution in isopropanol (for all patients) and in petrolatum (only one patient). It is interesting to underline that the reactions always occurred on the legs, even if the patients had applied the ointment elsewhere. We can hypothesize that the venom stasis dermatitis of the legs, associated with xerosis, may have favored the penetration of the drug through the skin, increasing the risk of allergic contact sensitization. Finally, cross-reactivity to other vitamin D3 analogue, tacalcitol, and calcitriol was excluded.

Recalcitrant scalp folliculitis: a possible role of herpes simplex virus type 2.

We report the case of a 70-year-old man with a 1 year history of relapsing folliculitis of the scalp. Bacteriological, mycological and the Tzanck tests from the lesions were negative. Histopathological study showed suppurative perifollicular flogosis. Virological cultures were negative, while HSV nested polymerase chain reaction (nPCR) assays made on swabs and histological sections from the scalp lesions demonstrated the presence of herpes simplex virus type-2 (HSV-2) in all samples. Skin swabs of healthy areas yielded negative results for HSV-2 infection. The folliculitis showed a marked and quick improvement after therapy with famciclovir suggesting a possible etiologic role of HSV-2 in the scalp folliculitis.

Contact dermatitis with clostridiopeptidase A contained in Noruxol ointment.

Clostridiopeptidase A, also called collagenase 1, is a proteolytic enzyme capable of digesting collagen. Preparations containing clostridiopeptidase A are used topically for the debridement of dermal ulcers, burns and other necrotic lesions to facilitate the formation of granulation tissue and subsequent epithelization. We observed 4 patients with a periulcerative eczema after repeated applications of Noruxol ointment (Smith & Nephew Ltd, L Hull, UK). Patch testing with Noruxol ointment as is and its excipients (soft paraffin and white petrolatum), as well as scaled dilutions of the main ingredient of this topical preparation, clostridiopeptidase A (Firma, Florence, Italy), showed doubtful reactions to Noruxol ointment in 3 patients and a positive reactions only in 1 patient. All patients showed positive reactions to clostridiopeptidase A 1% in pet. This study shows the sensitizing capacity of clostridiopeptidase A that should be tested in all patients with suspect sensitization to Noruxol ointment.

Occupational contact dermatitis to a limonene-based solvent in a histopathology technician.

Recently, D-limonene-based solvents are used as a safe alternative to xylene for histological and cytological application to dissolve paraffin. We report the case of a histopathology technician with a recalcitrant hand contact dermatitis strictly related to the use of a limonene-based solvent agent. Patch tests with SIDAPA (Italian Society of Allergological, Professional and Environmental Dermatology) standard series, limonene-based solvent used by the patient and D- and L-limonene (both oxidized and nonoxidized form) and with Giemsa and methylene blue stains were performed. Patch testing gave positive results to oxidized D- and L-limonene. The patient retired from work and promptly improved and healed the hand eczema. Subsequently, the potential occurrence of limonene oxidation products in the incriminated preparation was investigated using gas chromatography-mass spectrometry. While patch test showed positive reaction to oxidized limonene, chemical analysis failed to detect oxidized limonene in the preparations used by the patient. Considering the strict relation between the use of the preparations and the appearance of symptoms, we can assume that oxidized limonene may be produced during the handling of limonene-based products, especially in the presence of oxidants stains, frequently used in histological laboratories.

Long-term toxic effects of radiations: sarcomatoid carcinoma and multiple basal cell carcinoma of the limbs in chronic radiodermatitis.

A 73-year-old woman was referred to our attention for the presence of severe chronic lymphoedema and neoplastic lesions of the limbs. When she was 19 years old, the patient had undergone X-ray epilation of the limbs to remove unwanted body hair. The neoplastic lesions, observed 2 years before our observation, were excised, and histological examination revealed multiple basal cell carcinomas and a spindle squamous cell carcinoma on the left thigh. The case we observed offers some interesting points of consideration as it shows that in nonexposed areas cutaneous carcinomas can appear many years after irradiation and that the same treatment consequently requires careful follow-up for life. Another point of interest is the particular hystological aspect of neoplastic lesions in the site of radiodermatitis that requires in-depth immunohistochemical investigation for an exact diagnosis. Patients with previous treatment with ionizing radiation also in nonexposed areas need lifelong follow-up to identify cutaneous tumors at an early treatable stage.