The day of the triffids?

This is a case report of two children who presented with a widespread bullous erythematous rash secondary to exposure to the hogweed plant.

Use of in vivo confocal microscopy in malignant melanoma: an aid in diagnosis and assessment of surgical and nonsurgical therapeutic approaches.

BACKGROUND: Melanomas with poorly defined borders, lack of pigmentation, lentiginous extension, and location in cosmetically sensitive regions represent diagnostic and therapeutic challenges. Repeated surgical reexcisions are frequently required to achieve tumor-free margins. The use of reflectance mode confocal microscopy as an noninvasive method has shown to be a promising tool for diagnosing pigmented lesions in vivo. OBSERVATIONS: We report 3 clinical cases of melanoma: amelanotic melanoma (case 1), locally recurrent melanoma (case 2), and lentigo maligna melanoma (case 3). In case 1, in vivo confocal microscopy was instrumental in making the diagnosis and in monitoring the response to imiquimod therapy for in situ residual disease. It was also used to successfully delineate preoperative surgical margins in cases 2 and 3. CONCLUSION: As new methods for treating melanoma emerge and become more available, confocal microscopy can play a significant role by improving sensitivity in diagnosis, by increasing rates of successful initial excision, and by serving as a noninvasive means of monitoring therapy.

Reflectance confocal microscopy may differentiate acute allergic and irritant contact dermatitis in vivo.

BACKGROUND: Acute irritant contact dermatitis (ICD) and allergic contact dermatitis (ACD) may be difficult to distinguish by clinical or histologic assessment. Reflectance confocal microscopy (RCM) enables real-time, high-resolution skin imaging in vivo. OBJECTIVE: We sought to image, characterize, and distinguish acute ACD and ICD in vivo. METHODS: Volunteers with ACD were patch tested with an allergen and the irritant, sodium lauryl sulfate. RCM imaging and transepidermal water loss measurements were performed at 24 and 72 hours. Biopsy specimens were correlated with RCM images. RESULTS: Spongiosis, epidermal inflammatory cell infiltrate, and vesicle formation were observed in ACD and ICD. Compared with ACD, ICD showed greater disruption of the stratum corneum, and more parakeratosis. There was a significantly greater increase in transepidermal water loss for ICD compared with ACD. CONCLUSION: RCM is a promising tool for dynamic, noninvasive assessment and may help to differentiate acute ACD and sodium lauryl sulfate-induced ICD.

Changing paradigms in dermatology: confocal microscopy in clinical and surgical dermatology.

The current practice of pathology and dermatopathology depends upon the evaluation of tissue in some manner extirpated from the patient and then processed and stained. While high resolution of detail can be accomplished by this method, there are certain risks and disadvantages. Recent imaging techniques now allow for a potential of achieving noninvasive high-resolution analysis of lesions in situ in the patient. Of these, Reflectance mode confocal microscopy offers the highest resolution imaging comparable to routine histology. Being entirely non invasive, skin can be observed in its native, dynamic state. This chapter will review the fundamentals of in vivo confocal imaging and the clinical applications in general and surgical dermatology.

Quantitative ultrasonic methods for characterization of skin lesions in vivo.

Quantitative ultrasonic methods were studied for characterizing skin lesions in vivo using contact dermatitis as an example. The parameters studied include skin thickness, echogenicity, attenuation coefficient slope and parameters related to echo statistics (signal-to-noise ratio and shape parameters of Weibull, K and generalized gamma distributions). Data were collected using a high-frequency ultrasound (US) system (center frequency = 33 MHz). To compensate for depth-dependent diffraction effects, correction curves as a function of the distance between the transducer and the tissue were first empirically obtained. Diffraction-corrected quantitative parameters were then compared between healthy and affected skin of volunteers, who underwent patch testing for allergic and irritant contact dermatitis. A significant increase in skin thickness, decrease in echogenicity of the upper dermis and decrease in attenuation coefficient slope were found at the affected sites compared to those of healthy skin. However, no differences in parameters related to the echo statistics of the mid-dermis were found. These results indicate that a combination of quantitative ultrasonic parameters have the potential for extracting information for characterizing skin conditions.

Confocal histopathology of irritant contact dermatitis in vivo and the impact of skin color (black vs white).

BACKGROUND: The pathogenesis of irritant contact dermatitis and its modulation according to skin color is not well understood. Reflectance confocal microscopy (RCM) enables high-resolution, real-time, in-vivo imaging of human skin. OBJECTIVE: The goal of our study was to use RCM to determine whether susceptibility to irritant contact dermatitis differs between black and white skin. METHODS: Participants were placed in groups on the basis of skin color and the volar aspects of their forearms exposed to 1% and 4% sodium lauryl sulfate using Finn Chambers (Allerderm Laboratories Inc, Petaluma, Calif). They were evaluated at 6, 24, and 48 hours by RCM, transepidermal water loss, laser Doppler velocimetry, and routine histology. RESULTS: Participants with white skin had more severe clinical reactions than those with black skin. RCM revealed microscopic changes even without clinical evidence of irritation. Confocal features included parakeratosis, spongiosis, perivascular inflammatory infiltrate, and microvesicle formation, and these features were confirmed by routine histology. Also, participants with white skin had greater mean increases in transepidermal water loss after exposure to 4% sodium lauryl sulfate than did participants with black skin. CONCLUSION: In-vivo RCM can track early pathophysiologic events revealing differences between black and white skin during the development of irritant contact dermatitis, and may support the theory that those with black skin are more resistant to irritants.