Tinea nigra: A twenty-year incubation period?

A lesion of tinea nigra appeared on the sole twenty years after experimental inoculation.     

Gold therapy: dermatologic uses and toxicities.

Chrysotherapy is now an important approach to the management of pemphigus. The administration of gold compounds and their common toxicities are reviewed in this report.     

Langerhans cells in normal human skin capillaries

Cells with Langerhans granules are reported for the first time in normal human skin capillaries.     

Wound healing in dogs and cats

Dogs and cats suffer accidental wounds and surgical incisions in much the same manner as do humans. Ideally, the surgical incision and most accidental wounds are closed by sutures so that primary healing results. There are probably few differences in the healing processes in these sutured wounds in dogs and cats as compared with similar wounds in experimental animals such as rats, rabbits, and guinea pigs or in humans. Some surgical incisions and many accidental wounds must be left open, for various reasons, to heal as open wounds by contraction and epithelialization. It is in this mode of wound healing that similarities are seen between dogs and cats and the experimental animals such as rats, rabbits, and guinea pigs; however, major differences are seen between dogs and cats and humans.     

Secondary intention healing: an alternative to surgical repair

The choices of wound management are limited to either surgical repair or healing by secondary intention. Use of secondary intention healing is the oldest method, antedating the practice of medicine, but its use has declined since surgical techniques have been developed, refined, and popularized. Now secondary intention healing is used mostly for small superficial surgical wounds, lacerations, abrasions, chronic ulcers, and for wounds created by destructive methods such as electrodessication, cryosurgery, or chemical cautery. These applications are known well to dermatologists, but are less often used by other surgeons except when wounds have persisted after surgical repair, become infected, or result from necrosis of flaps or grafts.Even among dermatologic surgeons the interest in plastic and reconstructive techniques has overshadowed the importance and advantages of secondary intention healing. In the past several decades, only a small number of reports has appeared discussing the use of secondary intention healing for wounds that are traditionally managed by surgical repair.^1–10 These reports “rediscovered” the often amazing cosmetic results that follow secondary intention healing. There remains a reluctance to use this method to its fullest advantage. This is partly due to fear that open wounds heal inordinately slowly with complications of pain, bleeding, infection, and horrible scarring, and partly due to the conceit that our surgical skills are superior to Mother Nature's own way. There is an immediate gratification that occurs after the successful repair of a large wound. This feeling is difficult to sacrifice, especially if the results of secondary intention healing cannot be predicted. This chapter will review the advantages of secondary intention healing and provide a set of guidelines that will enable one to predict the cosmetic results of wounds allowed to heal by this method.     

Excision of melanoma after initial biopsy: An immunohistochemical study

An immunohistochemical method for the demonstration of S-100 protein was used to identify melanocytes in fourteen cases of malignant melanoma subsequently excised after initial punch biopsy. Although S-100 protein-containing cutaneous nerves and dermal dendritic cells could be identified within the area of dermal repair, there was no evidence of physical movement of atypical melanocytes or nevus cells downward into the scarified area. This study cannot confirm the concept that punch biopsy of melanoma physically seeds atypical cells into the dermis.     

Black and white human skin differences

This review of black and white human skin differences emphasizes the alleged importance of factors other than the obvious, i.e., skin color. Physicochemical differences and differences in susceptibility to irritants and allergens suggest a more resistant black than white skin. Differences appear to exist in the frequency of which several skin diseases occur among blacks and whites. A striking feature in this literature is the disagreement between authors. Common for much of this information is difficulty of interpretation, because of socioeconomic influences and other environmental factors.     

Uncombable hair syndrome: observations on response to biotin and occurrence in siblings with ectodermal dysplasia

Three children are reported with uncombable hair syndrome, consisting of slow-growing, straw-colored scalp hair that could not be combed flat. The hairs appeared normal on light microscopy but on scanning electron microscopy were triangular in cross section, with canal-like longitudinal depressions. Oral biotin, 0.3 mg three times a day, produced significant improvement after 4 months in one patient, with increased growth rate and with strength and combability of the hair, although the triangular shape remained. The other two patients were unique in having associated ectodermal dysplasia. Their hair slowly improved in appearance and combability over 5 years without biotin therapy.     

Hyperkeratosis of the nipple and areola

Hyperkeratosis of the nipple and areola is a rare condition. We report two cases of hyperkeratosis of the nipple and areola occurring in men with no underlying endocrinopathy or synthetic estrogenic drug therapy. Both patients demonstrated prompt resolution of the hyperkeratosis of the nipples with a keratolytic gel. Because our cases were not associated with ichthyosis or epidermal nevus, they best fit into the category of nevoid hyperkeratosis of the nipples.     

Drug eruptions presenting at sites of prior radiation damage (sunlight and electron beam)

Two patients are described in whom sunburn and electron beam radiodermatitis, respectively, were critical determinants in localizing the initial presentation of drug eruptions. In the first instance, a severe sunburn of the back and thighs was followed 7 months later by the appearance of a toxic epidermal necrolysis drug reaction to trimethoprim-sulfamethoxazole in the exact sites of the previous bullous sunburn reaction. In the second patient, a radiodermatitis of the left upper arm due to electron beam therapy for metastatic breast cancer was followed 7 weeks later by a codeine drug reaction confined to the area of the radiodermatitis. In both instances, oral rechallenge with the offending drug reproduced the eruption.     

Percutaneous penetration of dipyrithione in man: Effect of skin color (race)

A single chemical dose of dipyrithione (2,2′-dithiobispyridine-l, 1′-dioxide), 4 or 12 μ/cm² (containing 1 μCi of 2–6-¹⁴C material), was applied to the ventral forearm (intact skin, methyl alcohol vehicle [MeOH]), forehead (intact and stripped skin; cosmetic cream and MeOH vehicle), and scalp (intact and stripped skin; shampoo and MeOH vehicle) of human (white and black) volunteers. The urinary excretion of ¹⁴C was measured over the 7-day study period. Percutaneous penetration data were corrected for incomplete urinary recovery using data from intravenous studies (Wedig et al¹). The results obtained in this study suggested: (1) means from the complete analysis indicated 34% less (p < 0.02) absorbed by blacks; (2) less was absorbed by blacks than whites when seven out of seven means were compared within groups (p < 0.02); (3) a difference (p < 0.03) in penetration, blacks 47% lower than whites, between a cosmetic cream vehicle vs MeOH on the forehead; (4) on the scalp (MeOH vs shampoo vehicle) more was absorbed using MeOH (p < 0.02); (5) no evidence of a significant difference in penetration was noted when (a) the various anatomic sites were compared or (b) intact skin was compared with stripped skin.     

Electron microscopy of Merkel cell carcinoma from formalin-fixed tissue

Merkel cell carcinomas have characteristic, but not pathognomonic, histomorphologic features. The diagnosis can be confirmed by immunohistochemistry studies and electron microscopy. However, differential diagnostic problems often occur only after all tumor material has been fixed in formalin and embedded in paraffin, which gives poor tissue preservation for electron microscopy. Therefore, in addition to histologic and immunohistochemical studies, parallel ultrastructural investigations were performed on tumor specimens fixed in glutaraldehyde and routinely processed, for electron microscopy, on formalin-fixed tissue and on formalin-fixed paraffin blocks. Formalin fixation led to an almost complete loss of neurosecretory granules and cell membranes; however, the characteristic paranuclear whorls of intermediate filaments were retained in all tumors. Merkel cell carcinomas are immunoreactive for neuron-specific enolase (NSE), but NSE-antisera have only recently become commercially available. Cytokeratin is demonstrable as a paranuclear clump, and this feature was found in four out of six tumors. Thus histologic, immunohistochemical, and electron microscopy studies of formalin-fixed tissue are able to confirm the diagnosis of neuroendocrine Merkel cell carcinoma.