A potpourri of parasitic infestations.

Ectoparasitic infestations are common cutaneous problems. The vast majority of these are attributable to scabies and pediculosis. While these are usually readily recognizable, infestations caused by other ectoparasites, such as nonscabetic mites, may pose difficulty in diagnosis. In this article, we present a variety of ectoparasitic infestations that initially eluded diagnosis and review the gamut of ectoparasites that can cause eruptions in the skin.

Long-term efficacy and safety of Jessner's solution and 35% trichloroacetic acid vs 5% fluorouracil in the treatment of widespread facial actinic keratoses.

BACKGROUND: Few studies have examined the long-term efficacy of fluorouracil (FU) or chemical peels for the treatment of actinic keratoses (AK). Our earlier work examined the efficacy and safety of a medium-depth chemical peel compared with the standard regimen of topical FU in the treatment of widespread facial AK through 12 months. OBJECTIVES: To determine long-term efficacy of both treatments by extending our observations through 32 months. METHODS: Fifteen patients with severe facial actinic damage were treated on the left side with a single application of Jessner's solution and 35% trichloroacetic acid and on the right side with twice daily applications of 5% FU cream for 3 weeks. Parameters evaluated at 1, 6, 12, and 32 months included counts of visible AK, random skin biopsies from both treatment areas, development of intercurrent neoplasms, and surveys assessing sun exposure. RESULTS: Eight patients were available for reevaluation at 32 months. Both treatment sides showed a reduction in mean number of AK at 12 months followed by an increase in mean AK number between 12 and 32 months. Improvements in biopsies of clinically actinically damaged skin were seen in keratinocytic atypia, hyperkeratosis, parakeratosis, and inflammation at all treatment times during the study with both treatments. Three squamous cell carcinomas developed in the patients after initial treatment; one developed on the side treated with the peel, and two developed on the side treated with fluorouracil. Surveys failed to demonstrate an association between sun exposure and clinical response. CONCLUSION: Based on these findings, patient with widespread actinic keratoses treated with medium-depth chemical peel or with 5% FU should be reevaluated yearly or every 1.5 years for reappearance of AK and retreatment.

Sensitivity of diagnosis of malignant melanoma: a clinicopathologic study with a critical assessment of biopsy techniques.

Although most examples of cutaneous malignant melanoma are easily recognized by their clinical appearances, in some cases this serious neoplasm may clinically simulate other less serious forms of skin cancer or benign processes. This study was undertaken to assess both the sensitivity of clinical diagnosis of cutaneous malignant melanoma and the efficacy of biopsies of clinically unsuspected melanomas in yielding specimens on which complete and accurate histologic assessments could be made. A retrospective analysis of 1784 cases of histologically proven melanomas diagnosed between 1985 and 1990 was performed in search of lesions not clinically suspected. Biopsy techniques used to sample these lesions were subjected to critique of their efficacy in yielding specimens that could be accurately diagnosed and completely assessed histologically. Of 1784 histologically proven primary cutaneous melanomas, 583 were not clinically suspected, yielding a sensitivity of 67%. Clinical diagnosis included nevi (33%), no diagnosis (17%), multiple diagnoses (13%), basal cell carcinoma (12%), keratosis (9%), and lentigo (9%) among others. The biopsy methods used to sample these lesions were shave (56%), excisional (24%), punch (11%), curettage (2%), and undetermined (6%). Eighty-six percent of shave biopsies could be accurately assessed while only 32% of punches and no curettages provided sufficient material for both definitive and complete evaluation of melanomas. Eighteen percent of specimens histologically reviewed were considered inadequate for complete evaluation. In 34%, the actual diagnosis of melanoma was uncertain because of inability to assess diagnostic features as a consequence of the biopsy technique. Melanoma may be unsuspected clinically in a significant number of cases and may be mistaken for less serious cutaneous neoplasms.(ABSTRACT TRUNCATED AT 250 WORDS)

Histologic features and sensitivity of diagnosis of clinically unsuspected cutaneous melanoma.

The purpose of this study was to assess the sensitivity of clinical diagnosis of cutaneous malignant melanoma and to evaluate histologic characteristics of lesions not clinically diagnosed as such. Of 1,784 cases of histologically proven cutaneous malignant melanoma submitted routinely to a university dermatopathology laboratory between 1985 and 1990, 583 (33%) were not clinically suspected. The overall sensitivity in clinical diagnosis was 67%. Histologic features evaluated included presence of melanin, pagetoid spread of melanocytes, degree of inflammation, regression, presence and degree of sun damage as evidenced by solar elastosis, presence of melanin in the cornified layer, and coexisting nevus cells. Melanomas clinically thought to be nevi had less solar elastosis and most frequently had associated nevus cells. Those thought to be basal cell carcinomas had less melanin in lesions and less melanin in the cornified layer, and most often had foci of regression. Lesions thought to be keratoses showed melanin in the cornified layer 70% of the time, more often than any other type of lesion. Melanoma may be unsuspected clinically in a significant number of cases and can be mistaken for less serious cutaneous neoplasms. Histologic features of these lesions correlated well with original clinical diagnoses.