Acanthosis nigricans: a marker for hyperinsulinemia

A 12-year-old girl developed acanthosis nigricans due to increased levels of serum insulin. Hyperinsulinemia has been recognized as the underlying cause in most cases of acanthosis nigricans. In this paper we outline a typical clinical case with special regard to the proposed pathogenesis.

Pityrosporum ovale extracts increase interleukin-4, interleukin-10 and IgE synthesis in patients with atopic eczema

Evidence for a possible role of the lipophilic yeast Pityrosporum ovale in the pathophysiology of atopic eczema has been found both in laboratory and therapeutical studies. Positive type I prick test reactions to P. ovale correlate with the intensity of eczematous skin lesions in the head and neck regions of patients with atopic eczema. Furthermore, antifungal treatment has been shown to be helpful in atopic eczema. In the present study the effect of P. ovale on IgE synthesis and cytokine production (IL-2, IFN gamma, IL-4, IL-10) was investigated in patients with atopic eczema, in vitro. Eight patients with atopic eczema were studied; of these, 5 patients had specific IgE antibodies against P. ovale, as determined by fluoroimmunoassay (RAST). The control group consisted of 5 healthy non-atopic, P. ovale IgE-antibody-negative volunteers. Freshly isolated peripheral blood mononuclear cells (PBMC) were incubated in the presence of different antigen concentrations (0.01, 0.1, 1.0, 10 micrograms/l x 10(6) cells) of P. ovale. IgE contents in the cell culture supematants were significantly elevated in RAST(+) patients with atopic eczema (p < 0.05), compared with RAST(-) atopic eczema patients and healthy volunteers. Coincubation of P. ovale-stimulated PBMC with IL-4 (50 U/l/ 1 x 10(6) cells) resulted in a significantly higher IgE synthesis only in the RAST(+) atopic eczema patients. Additionally, incubation of PBMC from RAST(+) patients with atopic eczema led to an elevated synthesis of the TH2 related cytokines IL-4 and IL-10. Within the atopic eczema group, two subgroups differed markedly in their response to P. ovale antigen stimulation with a good correlation to the presence of specific IgE in serum and in vitro IL-4 and IL-10 production. The data support the assumption that P. ovale antigens might play a role in skin inflammation in at least a subgroup of patients with atopic eczema characterized by the presence of specific IgE antibodies to P. ovale.

Results of German multicenter study of antimicrobial susceptibilities of Trichophyton rubrum and Trichophyton mentagrophytes strains causing tinea unguium. German Collaborative Dermatophyte Drug Susceptibility Study Group

Thirty-two strains of Trichophyton rubrum and 16 strains of Trichophyton mentagrophytes isolated from patients with tinea unguium in various parts of Germany were subjected to a microdilution test with six systemic or topical antimycotic agents. Apart from griseofulvin, there were no species-specific differences between the two species. Terbinafine was the most active antimycotic agent, with a MIC not exceeding 0.05 micrograms/ml.

[Anaphylaxis caused by latex contamination from the wrapper of the cannula plaster]

A patient with pronounced latex allergy was admitted to hospital because of suspected drug allergy. He developed an anaphylactic reaction manifesting with skin reactions and difficulties in breathing immediately after an intravenous cannula was applied, although the doctor was wearing latex-free gloves. The envelope of the plaster with which the cannula was fixed was found to be the source of the latex responsible for the anaphylactic reaction. Latex contact with the skin was due either to latex contamination of the doctor's hands when opening the envelope or to the plaster itself. The case report demonstrates the difficulties arising both from the clinical reaction pattern of type I reactions to latex and from strict avoidance of latex-containing products and points out the necessity of latex declaration.

[Food-induced anaphylaxis in latex allergy]

Contact uticaria and anaphylactic reactions to latex-containing rubber products are being recognized with increasing frequency in all kinds of medical disciplines. Recently a number of reports have been published describing anaphylactic reactions to food items in patients with latex allergy. The cases of three patients who developed anaphylactic reactions to both latex and food items are presented, and the importance of the association of latex and cross-reactivity with food items is stressed. The food items that led to anaphylactic reactions were banana and avocado; banana, avocado and buckwheat; and banana, avocado and tomato. The cross-reactivity of latex to buckwheat and tomato has not been reported before.

Streptomycin-induced anaphylactic reaction during in vitro fertilization (IVF)

Indications for in vitro fertilization (IVF) have been cautiously extended over the years. IVF is usually considered to be a technically complex method with only minimal side-effects. We report the case of a woman who developed an anaphylactic reaction during IVF immediately after the embryo transfer.

Chronic urticaria due to nickel intake

A case of chronic urticaria is presented. The case of the disease was traced back to nickel intake by food as judged from type I and IV sensitization to nickel, a positive oral challenge test and long-standing, complete healing under a nickel-restrictive diet.

[Chronic mucocutaneous herpes simplex infection. Occurrence within the scope of liver-induced immunodeficiency]

Herpes simplex virus (HSV) infections causing severe disease are reported frequently in patients suffering from human immunodeficiency virus (HIV) infection. This disease pattern may also be seen in an immunocompromised disease state with other causes, however, as in the case presented in this paper. An 84-year-old woman had hepatic cirrhosis resulting from chronic hepatitis C virus infection. The woman developed ulcerative lesions in and around her mouth and in the genito-anal region, and these persisted for some months. Diagnosis of HSV infection was not obtained until after extensive laboratory investigations. Aciclovir infusion therapy started immediately afterwards led to dramatic improvement of the skin and mucous membrane changes. Complete clearing of lesions was not obtained, however, because the patient died as a result of the immunosuppression.

Relapsing severe Trichophyton rubrum infections in an immunocompromised host: evidence of onychomycosis as a source of reinfection based on lectin typing

A 64-year-old patient developed recurrent (about 3-6 times a year) generalized skin lesions due to Trichophyton rubrum during long-term steroid treatment of lung fibrosis. Additionally, he suffered for years from onychomycosis of all toes. In the past, short-term internal treatment with griseofulvin and ketoconazole resulted in fast clearing of skin symptoms. Since 1991 relapses have been treated with itraconazole orally. In 1992 material was collected from diseased nails and toe and other skin lesions during three severe attacks of fungal infections and in addition once from toenails during a period without skin manifestations. Trichophyton rubrum was isolated from each sample. Lectin typing of the isolates using five lectins of plant origin resulted in identical lectin patterns for all isolates, thus localizing the toenails as the source of reinfection. The results indicate that lectin typing may play an important role in clinical and epidemiological analysis of dermatophytes.

Beta-adrenergic receptors in psoriasis: evidence for down-regulation in lesional skin

Lesional psoriatic skin displays reduced responsiveness to beta-adrenergic stimulating agents. To elucidate whether the receptor protein itself is responsible for this, lesional and non-lesional psoriatic skin was investigated ex vivo for maximal beta-adrenergic binding density (Bmax) and beta-adrenergic binding affinity (KD). Epidermal crude membrane homogenates (ECMH) were prepared from split-thickness skin biopsies and saturated with the lipophilic beta-adrenergic antagonist (-)-125I-iodocyanopindolol (ICYP) as radioligand. Specific binding was saturable and Scatchard transformation of the binding data revealed a homogeneous class of beta-adrenergic receptors in all nine experiments. The maximal beta-adrenergic binding density was significantly less in lesional than in non-lesional psoriatic skin (Bmax = 49.7 +/- 7.2 fmol/mg protein vs. 67.1 +/- 2.2 fmol/mg protein, n = 9, P < 0.05). The binding affinity was similar in lesional and in non-lesional skin (KD = 9.0 +/- 1.5 pmol/l vs. 8.0 +/- 0.9 pmol/l). These results could at least partially explain the reduced responsiveness of the beta-adrenergic system in lesional psoriatic skin seen after stimulation with beta-adrenergic agonists.

The suppressive effect of serum samples from patients with chancroid on human mononuclear cells correlates with the clinical picture and is interleukin-2-dependent

Plasma samples from patients with chancroid diagnosed both on clinical and microbiological grounds were assessed for their ability to inhibit mitogen-induced proliferation of human lymphocytes from healthy donors. All serum samples analysed suppressed phytohaemagglutinin A (PHA) blastogenic response. A significant difference in the observed extent was seen when serum samples from patients with and without associated lymphadenopathy were compared (P < 0.05). Using an interleukin-2 (IL-2)-dependent cell line it could be demonstrated that the addition of patients' plasma to cultured cells markedly depressed mitogen-induced IL-2 synthesis. Results presented suggest that cell-mediated mechanisms play a role in the pathogenesis of infection due to Haemophilus ducreyi.

Pathophysiological concept of Haemophilus ducreyi infection (chancroid)

Our knowledge concerning the pathogenesis of infection due to Haemophilus ducreyi is incomplete. In order to produce disease, H. ducreyi must presumably penetrate the skin of the external genitalia, colonize subcutaneous tissues, then produce tissue damage which results in ulcer formation. Penetration of the normal skin most likely occurs via minor abrasions. Adherence of H. ducreyi to different cell lines in vitro has been described, and might be mediated by adhesions such as pili or haemagglutinins. In addition, binding to extracellular matrix proteins has also been reported. Extracellular tissue-degrading enzymes were absent from broth culture supernatants of H. ducreyi. Such supernatants also failed to produce cytopathic effects with established or primary cell lines. Both live and heat-killed H. ducreyi organisms were able to produce lesions in a rabbit or a mouse model, although ulcer formation was dependent on viable H. ducreyi organisms in a recently introduced temperature-dependent rabbit model. With an excessive supply of iron, a more prolonged localized inflammatory disease effect was observed. Results derived from a subcutaneous chamber model demonstrated considerable changes in the expression of outer membrane proteins combined with antibody modulation during in vivo growth of H. ducreyi. These might be important factors for maintenance of infection in the human host particularly as these changes also occur in humans. Despite an increased knowledge of the pathogenesis of chancroid, important questions such as growth requirements, bubo-formation, role of cell-mediated immunity and ulcer formation are still unanswered. The application of molecular biological techniques in order to study these problems will be helpful.

Atopic eczema: role of microorganisms on the skin surface

The pathophysiology of atopic eczema (AE) is still poorly understood. One possible concept favors IgE-mediated reactivity towards allergens that enter the skin from the outside or through the blood. Microorganisms of the cutaneous flora also might represent a stimulus for allergic skin reactions. Abnormal bacterial skin colonization is a characteristic feature of AE. Staphylococcus aureus (S. aureus) is the most common pathogen. Binding to host cells involves special receptors, such as fibronectin or laminin. Specific IgE antibodies to S. aureus can be detected in the blood. Whereas the clinical relevance of anti-staphylococcal antibodies is still controversial, specific IgE antibodies to Pityrosporum species as well as positive type I prick test reactions to these yeasts seem to correlate with the intensity of eczematous lesions in the head and neck regions of patients with AE. Both antimicrobial and antifungal treatment has been shown helpful in some cases of AE.

Binding of Haemophilus ducreyi to extracellular matrix proteins

A collection of Haemophilus ducreyi isolates were screened for the ability to bind to fibrinogen, fibronectin, collagen, gelatin and laminin by a particle agglutination test using latex beads coated with the individual proteins. Thirteen of 21 isolates reacted with all five extracellular matrix proteins. Binding of organisms to protein-coated latex beads was inhibited by pretreatment of the bacteria with detergent, trypsin or boiling. Two isolates did not bind to collagen and gelatin with one of these not reacting with laminin either. Seven strains which failed to react with laminin did not express pili when examined by electron microscopy. This observation suggests a specific interaction with the pili of H. ducreyi.

Folliculitis decalvans. Long-lasting response to combined therapy with fusidic acid and zinc

In 3 patients, the diagnosis of folliculitis decalvans was based on clinical, histopathological and laboratory criteria. All patients responded to a combination therapy consisting of oral and topical fusidic acid and oral zinc sulphate. The follow-up period exceeded more than one year.

Atypical presentation of co-existent Haemophilus ducreyi and Treponema pallidum infection in an HIV-positive male

A 25-year-old homosexual black male presented with asymmetrical perianal ulceration of uncertain clinical origin. Indepth microbiological examination revealed the combined presence of Haemophilus ducreyi and Treponema pallidum. The atypical clinical appearance may have been due to the changed immunological status of the host's being infected with Human Immunodeficiency Virus.

Lack of immunoglobulin A1 protease production by Haemophilus ducreyi

A collection of 20 strains of Haemophilus ducreyi including freshly isolated, low-passage and multi-passage reference strains was examined for immunoglobulin A1 protease production by SDS-PAGE and immunoblotting. None of the strains demonstrated IgA1 protease activity despite the fact that different culture media were used. By direct immunofluorescence testing, binding of IgA to Haemophilus ducreyi organisms could be demonstrated.