Evolution of IESs and scrambling in the actin I gene in hypotrichous ciliates.

Germ-line (micronuclear) genes in hypotrichous ciliates are interrupted by numerous, short, noncoding, AT-rich segments called internal eliminated segments, or IESs. IESs divide a gene into macronuclear destined segments, or MDSs. IESs are excised from micronuclear genes, and the MDSs are spliced when a micronuclear genome is processed into a macronuclear genome after cell mating. In the micronuclear version of the actin I gene intramolecular recombination between IESs during evolution has put MDSs into a scrambled disorder in some but not all hypotrichs. Studies using rDNA sequences to define phylogenetic relationships among eight hypotrichs suggests that evolution of the micronuclear actin I gene proceeds by successive addition of IESs in earlier diverging species, without MDS scrambling. Continued addition of IESs and recombination among IESs in later diverging species produced actin I genes with scrambled MDSs. Subsequent to MDS scrambling, additional IESs were inserted into the more recently evolved species. Thus, IES insertions and gene scrambling occur in a progressive manner during species evolution to produce micronuclear actin I genes of increasing structural complexity.

Mycosis fungoides bullosa: report of a case and review of the literature.

Mycosis fungoides, the most common type of cutaneous T-cell lymphoma, can manifest in a variety of clinical and histologic forms. Presentation with vesiculobullous lesions is extremely rare. We report the ninth documented case of mycosis fungoides bullosa in which other concomitant autoimmune blistering diseases were ruled out by negative immunofluorescence. All previously reported cases in the world literature since the first in 1887 are reviewed. We recommend the following defining criteria for the disease: (1) clinically apparent vesiculobullous lesions, with or without typical mycosis fungoides lesions (patches, plaques, tumors); (2) typical histologic features of mycosis fungoides (atypical lyphoid cells, epidermotropism, Pautrier's microabscesses) with intraepidermal or subepidermal blisters; (3) negative immunofluorescence (both direct and indirect, if possible) to rule out concomitant autoimmune bullous diseases; (4) negative evaluation for other possible causes of vesiculobullous lesions (eg, medications, bacterial or viral infection, porphyria, phototherapy).

Extrafacial granuloma faciale: report of a case and response to treatment.

Granuloma faciale (GF) is a rather uncommon form of chronic vasculitis that infrequently involves extrafacial sites. Treatment of this disease is extremely challenging. We report a case of GF with extrafacial lesions and a unique response to treatment. The diseases that are clinical and histologic mimics of this disorder, as well as a review of various treatment modalities, are discussed.

Male pattern baldness.

BACKGROUND: Male pattern baldness, or androgenetic alopecia (AGA) in men, occurs with varying severity and age of onset. Two new treatments widely available as alternatives to 2% minoxidil are 1 mg finasteride and topical 5% minoxidil. Finasteride is a 5 alpha-reductase inhibitor available by prescription only; 5% minoxidil is available over the counter. METHODS: We searched MEDLINE to identify all articles on AGA and its pharmacologic therapies. RESULTS: We found limited information on AGA in peer review medical journals. Associated diseases include psychologic disorders and coronary heart disease. Hair growth is unpredictable and limited for all pharmacologic therapies, with the vast majority of treatment studies being industry sponsored. CONCLUSION: AGA is not easy to treat. Finasteride and 5% minoxidil offer new therapeutic options to the balding man. Treatment options may improve as new drugs are further investigated.

Ulcerated atrophic striae from etretinate.

Oral retinoids such as etretinate and acitretin are commonly associated with dose-dependent, mucocutaneous side effects such as dryness, peeling, and fragility. Although these effects can be extreme in some patients and even require discontinuation of treatment, thinning of skin to the point of atrophy and ulceration has never been reported in the English literature. We present the case of a patient with psoriasis in whom ulcerated atrophic striae developed during etretinate therapy. After discontinuation of etretinate, all cutaneous ulcers resolved. Subsequently, the patient had a favorable response to oral calcitriol (1,25-dihydroxy vitamin D3), a novel therapy for psoriasis.

Evaluation and management of the "red face". Interview by K. Watsky and M. Rothe.

Patients presenting with a "red face" challenge clinicians to consider a broad differential diagnosis that includes contact dermatitis. The diagnosis may be obscured or complicated by underlying actinic damage or rosacea. Unraveling this Gordian knot to arrive at a precise and accurate diagnosis takes patience and practice. The collective experience of our invited group of expert clinicians sheds light on this process.

Contact dermatitis for primary care providers.

Contact dermatitis is an eczematous dermatitis developing at a site where the skin has been in direct contact with the cutaneous irritant or allergen from the environment. Irritant contact dermatitis (ICD) is the most common form. Allergic contact dermatitis (ACD) is inflammation of the skin caused by an antigen that elicits a type IV hypersensitivity reaction. Clinical evaluation and judgment are a critical part of the process. Patch testing in an objective method to aid in differentiating ACD from ICD and of verifying responsible allergens.

Pemphigus foliaceus and renal cell carcinoma.

It is possible to distinguish the various forms of pemphigus from one another using clinical, histologic, and immunologic criteria. Paraneoplastic pemphigus, a recently defined type that is severe and often fatal, is associated with an underlying malignancy. We present the second reported case of pemphigus associated with renal cell carcinoma. We do not believe that either case represents paraneoplastic pemphigus, which suggests the possibility of some other link between these two diseases.

Leg ulcers: a common problem with sometimes uncommon etiologies.

In the U.S., leg ulcers present a significant clinical problem, occurring at a rate of approximately 600,000 new cases per year. In most cases, the cause of ulceration is venous or arterial in nature. One uncommon but significant cause of leg ulcers is sqaumous cell carcinoma (SCC). Although the incidence of SCC is higher in white than black populations, blacks with SCC typically exhibit involvement of areas of the skin that are not chronically sun-exposed, especially the lower extremeties. Predisposing factors include burn scars, chronic infection or ulceration, and chronic discoid lupus erythematosus. Leg ulcers of atypical presentation or those that fail to heal should alert the clinician to consider uncommon etiologies.

Lichen striatus: simultaneous occurrence in two nonrelated siblings.

Lichen striatus is an uncommon, self-limited eruption of unknown etiology. What role genetic or environmental influences play in its pathogenesis is unclear. We report two nonrelated, adopted children living in the same household who simultaneously developed lichen striatus.

Seabather's eruption. Clinical, histologic, and immunologic features.

BACKGROUND: Seabather's eruption (SE) is a highly pruritic eruption under swimwear that occurs after bathing in the ocean. Its cause has been unknown. Few data have been collected since the classic description by Sams in 1949. OBJECTIVE: Our purpose was to describe the clinical and histopathologic findings in SE and to confirm the cause. METHODS: Patients with a pruritic eruption that developed after swimming were seen within 1 week of onset. Skin biopsy specimens and sera were obtained in selected cases. Water samples taken from areas of active SE outbreaks were examined for a causative organism. Sera were tested by enzyme-linked immunosorbent assay for reactivity to this organism. RESULTS: In southeast Florida, during a 4-month period, 70 patients with SE were seen. Inflammatory papules and pruritus were noted within hours of exposure. Eruptions were maximal in areas covered by a bathing suit. Children were more likely than adults to have systemic symptoms. The average duration of the eruption and pruritus was 12.5 days, with recurrences in 4.3% of patients. Histopathologic examination revealed a superficial and deep perivascular and interstitial infiltrate consisting of lymphocytes, neutrophils, and eosinophils. Water samples contained many cnidarian larvae, later grown to maturity and identified as Linuche unguiculata (thimble jellyfish). Enzyme-linked immunosorbent assay demonstrated in patients' sera high IgG levels specific for L. unguiculata. CONCLUSION: SE is a severely pruritic marine dermatosis that resolves spontaneously within 2 weeks. Therapy is symptomatic but often ineffective. Sera from affected persons showed specific reactivity to L. unguiculata.

The prognosis of occupational contact dermatitis.

Despite the development of new drugs and improvements in working conditions, the prognosis for recovery from contact dermatitis has not changed significantly over the past 50 years. This chapter reviews the prognosis for both irritant and allergic contact dermatitis and discusses the main reasons that contact dermatitis persists, including misdiagnosis and continued exposure to irritants and allergens.