Segmental neurofibromatosis in association with nevus sebaceus of Jadassohn.

We describe an unusual case involving the simultaneous occurrence of segmental neurofibromatosis (Type V NF) in a patient with a large nevus sebaceus of Jadassohn in the same physical distribution. Causative mechanisms of development of these 2 genetic disorders have not been definitively linked. Factors producing these diseases probably involve similar tissues at the same point in development because both have been reported in association with central nervous system anomalies and have been classified among the neurocutaneous syndromes. This is a case of a nevus sebaceus occurring in association with and in the same physical distribution as segmental NF. These disorders most likely represent a spectrum of disease within the phakomatoses.

Current treatments for scabies and pediculosis.

Scabies and lice have afflicted man since ancient times. Permethrin is generally the treatment of choice for head lice and scabies, because of its residual effect. Toxicity and absorption are minimal. Ivermectin should be reserved for cases where permethrin fails.

The spectrum of neurocristic cutaneous hamartoma: clinicopathologic and immunohistochemical study of three cases.

Neurocristic cutaneous hamartomas result from aberrant development of the neuromesenchyme. Thus, the elements within these tumors reflect the spectrum of differentiation that results from migration of neural crest-derived cells. We present three cases, in addition to routine hematoxylin-eosin staining, a battery of immunohistochemical staining, including S-100 protein, HMB-45, EMA, CD34, and neurofilament-protein stains, was performed on each specimen. A dermal melanocytic component was the dominant feature of two of these lesions, while neurosusenticular and neuromesenchymal components dominated in one tumor. Both tumors that developed on the scalp showed effects on the overlying epidermis and/or on adnexal development. The melanocytic component was positive for S-100 protein and HMB-45. The surrounding stroma showed tactoid bodies and increased CD34 staining. Neurocristic cutaneous hamartomas represent dysplastic development of neural crest-derived cells. Although melanocytic cells have been previously reported to be the dominant cell population, neurosusentacular and neuromesenchymal cells also may be the principal component. In cephalic areas, the neuromesenchyme may not only be an important component of the tumor, but may also effect the development of the overlying epithelium and adnexal structures. Although none of these cases presents evidence of malignant transformation, identification of these tumors could be important if malignant transformation results in the development of tumors with a distinctive biologic behavior.

A risk-benefit assessment of agents used in the treatment of scabies.

Permethrin is probably the most effective topical treatment for scabies. There is little microbial resistance to the drug, and it is highly effective. Toxicity is limited to occasional contact dermatitis. Similarly, oral ivermectin 200 micrograms/kg is extremely effective. Oral administration eliminates the need to be certain that medication has been applied properly. Toxicity has been very limited. It is not available in the US for human use in scabies at this time. The toxicity of most of other treatments that are available has not been studied carefully. Sulphur 6% in petrolatum is recommended as safe, but there are no good studies to confirm this. Sulphur is probably the medication of choice when cost is the overriding concern. Crotamiton and benzyl benzoate are probably safe, but are not as effective as permethrin. Lindane has some potential CNS toxicity if used incorrectly, and must be used carefully on damaged skin to avoid excessive absorption. It is important to stress that all household and sexual contacts must be treated, whether or not they have symptoms. Proper application of topical medications must be achieved, including under the fingernails, and up to the edge of all body orifices.

Tinea incognito: an update on Majocchi granuloma.

Majocchi granuloma was described naturally in situations of occlusion and later from superficial trauma such as shaving. More recently, the disease has occurred in the immunocompromised patient. Iatrogenic disease (tinea incognito) is a new and more subtle form.

Unusual subcutaneous infections.

This article reviews various unusual subcutaneous infections, including rhinosporidiosis, lobomycosis, and protothecosis. Clinical findings, pathology, mycology, and treatment are discussed for each disease.

Zygomycosis.

In our increasingly immunocompromised populations, zygomycosis is becoming more common. It occurs in two forms. Mucormycosis is an acute, necrotic, rapidly progressive disease of the immunocompromised patient that may lead quickly to death. Entomophthoromycosis is a chronic, slowly progressive subcutaneous disease seen mostly in immunocompetent patients living in tropical climates.

Scabies: diagnosis and treatment.

Scabies is a common, severely pruritic, contagious disorder. Treatment must be careful and methodical to avoid continuing infestation. Patients and their contacts must be treated, and clothing changed. Failure to discover all the contacts leads to continuing spread of the disease.

Sexually transmitted diseases of the vulva.

Sexually transmitted disorders may present on the vulva as ulcers, rashes, edema, adenopathy, or pruritus. Clinical and laboratory skills are needed to distinguish one from another so that the proper treatment is selected and further venereal spread is prevented.