Ernesto Gonzalez

Allergic contact dermatitis: Correlation of in vivo confocal imaging to routine histology

BACKGROUND Allergic contact dermatitis (ACD) is a common and often challenging clinical problem. In vivo near-infrared confocal reflectance microscopy (CM) is a new vital microscopy technique. OBJECTIVE CM was used to evaluate acute ACD. METHODS Patch testing by means of Finn Chambers technique was performed in 5 subjects to induce an acute allergic skin reaction. Noninvasive CM images from normal and eczematous skin were sequentially recorded before and after removal of the Finn Chambers. RESULTS The epidermis and papillary dermis were clearly seen in high resolution. Retention of nuclei in stratum corneum, epidermal edema with microvesicle formation, and transepidermal migration of inflammatory cells were observed in vivo. Isolated dendritic cells were present in the ACD sites of 2 subjects, with morphology, size, and location consistent with Langerhans cells. Dermal vasodilation was observed as well. CONCLUSION CM is a useful tool to study ACD and may be able to track Langerhans cell activation.

Drug photosensitivity, idiopathic photodermatoses, and sunscreens

Photosensitization may be defined as a process in which a reaction to normally innocuous radiation is induced by the introduction of a specific radiation-absorbing substance (the photosensitizer) that causes another component (the substrate) to be changed by the radiation. This review focuses on photosensitization produced by exogenous chemicals. Idiopathic photodermatoses, including polymorphous light eruption and its variants, solar urticaria and chronic actinic dermatitis, are also discussed. Clinical recognition patterns of the photodermatoses are stressed as well as several diagnostic procedures available for confirmation of the condition. Finally, descriptions, therapeutic uses, and adverse reactions of sunscreens are provided.

Comparison of PUVA and beta-carotene in the treatment of polymorphous light eruption

Therapy with oral psoralen photochemotherapy (PUVA) and oral beta‐carotene was compared in 29 patients with polymorphous light eruption. Complete remission occurred in 90% (9/ro) of those treated with PUVA and in 32% (6/19) treated with beta‐carotene. In the six patients who were treated in consecutive years with both modalities all had remission with PUVA while only two had remissions with beta‐carotene.

Laser treatment of tattoos in darkly pigmented patients: Efficacy and side effects

BACKGROUND Many modalities for the treatment of tattoos and pigmented lesions produce a greater risk of complications in Fitzpatrick types V and VI skin because of an increased incidence of adverse pigmentary changes and keloidal scarring. In fair-skinned persons Q-switched lasers have proved effective in removing pigmented lesions and tattoos without scarring. OBJECTIVE This study was conducted to determine the efficacy and effects of Q-switched lasers on a small series of darkly pigmented patients with tattoos. METHODS Four patients of Ethiopian origin with facial and neck tribal tattoos were treated with both the Q-switched ruby and Nd:YAG lasers. One black woman with a multicolored tattoo on the mid chest was treated with the Q-switched ruby laser. RESULTS Clearing of all lesions was seen. The treatments did not result in scarring or permanent pigment changes other than the ones intended. CONCLUSION Our results indicate that in darkly pigmented patients, Q-switched laser treatment of tattoos can be performed successfully. The longer wavelength Q-switched Nd:YAG laser is recommended when removing tattoos in darker complected persons. A test treatment is advised before treatment of large skin areas.

Treatment of pyogenic granulomas with the 585 nm pulsed dye laser

BACKGROUND Current therapeutic alternatives for pyogenic granulomas include surgical excision, electrodesiccation and curettage, cryotherapy, and ablation with CO2 or continuous-wave vascular lasers. OBJECTIVE Our purpose was to investigate the use of the 585 nm flashlamp-pumped pulsed dye laser (585 nm PDL) for the treatment of pyogenic granulomas in terms of efficacy, advantages in technique, and side effects. METHODS Eighteen patients with symptomatic pyogenic granulomas in a variety of locations were treated with the 585 nm PDL and examined. RESULTS Sixteen of 18 treated patients demonstrated both symptomatic and clinical clearing of the lesions with excellent cosmetic results after treatment. The two patients who dropped out after one to two 585 nm PDL treatments were eventually treated successfully with electrodesiccation and curettage. No postoperative complications and no persistent pigmentary changes or scarring were observed. The procedure required no anesthesia, and postoperative care was limited to the application of a topical antibiotic ointment. CONCLUSION Our experience suggests that treatment of pyogenic granulomas with the 585 nm PDL is a safe, effective, and reasonable alternative to conventional therapy.

Noninvasive evaluation of allergic and irritant contact dermatitis by in vivo reflectance confocal microscopy.

Background: The clinical differentiation of allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD) is often difficult to accomplish. Reflectance‐mode confocal microscopy (RCM) is an imaging technique that has previously been used to examine ACD and ICD noninvasively in vivo. Objective: To determine characteristic features of ACD and ICD and their kinetic evolution over time. Ethnic susceptibility to contact irritants such as sodium lauryl sulfate and Ivory dishwashing liquid was evaluated noninvasively, and the sensitivity and specificity of RCM parameters were analyzed in a clinical context and in reference to patch testing. Methods: Subjects were patch‐tested with allergens, irritants, and controls. Clinical scoring and RCM evaluation were performed at various time points, assessing stratum corneum (SC) disruption, spongiosis, exocytosis, vesicle formation, and epidermal thickness. Results: RCM features of both ACD and ICD include spongiosis, exocytosis, vesicle formation, and blood vessel dilatation. SC disruption, epidermal necrosis, and hyperproliferation are hallmarks of ICD whereas ACD more typically presents with vesicle formation. Patients with ICD showed a more rapid recovery than those with ACD. When tested with Ivory soap at selected concentrations, Caucasians, when compared to African Americans, showed significantly lower clinical thresholds for ICD and features that were more severe. Conclusions: RCM may be a promising new technology for longitudinal noninvasive studies of contact dermatitis (CD). Using a diagnostic algorithm and those parameters with high sensitivity for CD, RCM may facilitate the differentiation of acute ACD and ICD. RCM can reliably visualize cutaneous changes at subclinical degrees of CD, which suggests a possible role for RCM as an adjunctive tool in CD diagnosis. The results of this pilot study also indicate ethnic differences in the response to contact irritants. However, further studies are needed to substantiate the relevance and clinical applicability of our findings.

Confocal imaging of sebaceous gland hyperplasia in vivo to assess efficacy and mechanism of pulsed dye laser treatment

This case demonstrates, for the first time, the use of in vivo confocal imaging to assess the efficacy of laser treatment of a skin lesion with a vascular component.

Treatment of telangiectases and other benign vascular lesions with the 577 nm pulsed dye laser

BACKGROUND This study was undertaken to evaluate the effectiveness and safety of the 577 nm pulsed dye laser in the treatment of various vascular lesions of the face. OBJECTIVE Our purpose was to make observations on the effects of different variables that could affect response. METHODS Ninety-two adults with telangiectases of the face were sequentially selected for treatment according to a protocol previously established. Evaluation consisted of visual inspection by two investigators, and before and after photographs at 2-months intervals. A few patients with other vascular lesions were also treated and reported. RESULTS Ninety-one percent of the patients (84 of 92) showed good to excellent response after a single treatment. Recurrence occurred in 2%. Atrophy of the skin occurred in 2%. Venous lakes, pyogenic granulomas, and mucosal vascular malformations showed significant improvement. CONCLUSION The 577 nm pulsed dye laser is effective and safe for vascular lesions of the face.

Prevalence of skin disease in a cohort of shelter-based homeless men

BACKGROUND Cutaneous disease is a frequent cause of morbidity in homeless people. A variety of infectious and noninfectious conditions have been described in this population that are exacerbated by malnutrition, exposure to hazardous environment, psychiatric disease, physical injuries, and limited access to health care. OBJECTIVE Our purpose was to study the prevalence of skin disease in a selected group of the homeless population. METHODS We evaluated skin diseases in a cohort of 142 homeless men who were staying overnight in a major Boston homeless shelter for men over a period of 3 months (March-June 1992). The subjects participated in the study by volunteering for a free skin examination. Completion of a detailed questionnaire on age, race, duration of homelessness, and general medical status was followed by a thorough skin examination performed by dermatologists. RESULTS The most prevalent skin diseases in the examined population were tinea pedis (38%), pitted keratolysis of the feet (20.4%), traumatic injuries (19.7%), toenail onychomycosis (15.4%), acne vulgaris (18.3%), and seborrheic dermatitis (13.3%). CONCLUSION To our surprise the majority of patients had relatively normal findings from skin examinations with only a few pathologic findings, most often related to poor foot hygiene and long-term exposure to moisture. We attribute the relatively good condition of our cohort to the excellent care provided by the shelter with regard to clothing, cleaning facilities, and medical care. Our findings may represent the prevalence of skin diseases in shelter-based homeless but not in street homeless persons who are likely to have much poorer hygiene and perhaps more skin disease.

Treatment of Nevus Spilus with the Q-switched Ruby Laser

BACKGROUND Q‐switched lasers have shown to be effective in the removal of unwanted cutaneous pigmentation. Benign cutaneous pigmented lesions represent a heterogeneous group. Nevus spilus is a relatively uncommon pigmented lesion characterized by dark, hyperpigmented dots scattered over a tan‐colored macule. OBJECTIVE A cohort of patients with nevus spilus was studied to determine the effects of Q‐switched ruby and Q‐switched Nd:YAG laser treatment on clearance of pigment and to evaluate potential side effects. METHODS Sir patients with nevus spilus were treated with the Q‐switched ruby laser (QSR). In addition, three lesions received a test treatment with the Q‐switched Nd:YAG (QSYAG) laser at 532 or 1064 nm. The results of treatment were documented during follow up visits. RESULTS Most lesions showed a near‐complete or complete response to laser treatment. In one case partial hyperpigmentation occurred after treatment and in one case no follow‐up could be obtained. In the three cases that received both QSR and QSYAG laser treatment, the QSR laser was shown to be the most effective in removing pigment. CONCLUSION Nevus spilus can be treated effectively with the Q‐switched ruby laser.