IL-36 signaling in keratinocytes controls early IL-23 production in psoriasis-like dermatitis

IL-36R signaling plays an important role in the pathogenesis of psoriasis. We ought to assess the specific function of IL-36R in keratinocytes for the pathology of Aldara-induced psoriasis-like dermatitis. Il36r ΔK mice presenting deletion of IL-36R in keratinocytes were similarly resistant to Aldara-induced ear inflammation as Il36r -/- mice, but acanthosis was only prevented in Il36r -/- mice. FACS analysis revealed that IL-36R signaling in keratinocytes is mandatory for early neutrophil infiltration in Aldara-treated ears. RNASeq and qRT-PCR experiments demonstrated the crucial role of IL-36R signaling in keratinocytes for induction of IL-23, IL-17, and IL-22 at early time points. Taken together, our results demonstrate that IL-36R signaling in keratinocytes plays a major role in the induction of Aldara-induced psoriasis-like dermatitis by triggering early production of IL-23/IL-17/IL-22 cytokines and neutrophil infiltration.

Evaluation of a spontaneous canine model of immunoglobulin E-mediated food hypersensitivity: dynamic changes in serum and fecal allergen-specific immunoglobulin E values relative to dietary change

The purpose of the pilot study reported here was to evaluate serum and fecal total and allergen-specific immunoglobulin E (IgE) responses to dietary change in five Maltese x beagle dogs with suspected food hypersensitivity, compared with those of five clinically normal dogs. Clinical parameters (pruritus, otitis, and diarrhea) improved in the Maltese x beagle dogs during feeding of a novel diet, and signs were exacerbated by oral allergen provocation. Relative concentrations of serum and fecal wheat-, corn-, and milk-specific IgE were determined by use of an ELISA. The onset of clinical signs of disease was accompanied by an increase in serum allergen-specific IgE concentrations. In contrast, changes in clinical signs of disease or allergen-specific IgE values were not seen in the control group undergoing the same regimen. Total serum IgE concentration was measured by use of the ELISA, and comparison with known quantities of a monoclonal IgE allowed absolute values to be reported. Values were high in the Maltese x beagle colony (7 to 34 microg/ml), compared with those in the control dogs (0.7 to 6 microg/ml). Total serum and total fecal IgE concentrations did not change in either group during the study. Although allergen-specific IgE was detected in the feces of both groups, significant interassay variability made interpretation of the results difficult. The authors concluded that these Maltese x beagle dogs satisfied the currently recognized clinical criteria for the diagnosis of canine food hypersensitivity. Furthermore, the clinical and serologic responses seen in these dogs in response to oral allergen provocation suggest that this may be a useful model for the study of spontaneous food hypersensitivity.

Allergy for the otologist. External canal to inner ear

Allergy may affect the outer, the middle, or the inner ear. Although the otologic manifestations of allergy are not by themselves diagnostic, the history, including family history and associated symptoms in other target organs, will often help lead to the correct diagnosis and institution of therapy. Patients with significant and chronic symptoms, including those with labyrinthine symptoms of allergy, will respond well to specific immunotherapy and/or dietary elimination.

Characteristics of cerumen in diabetic patients: a key to understanding malignant external otitis?

Malignant externa otitis is a potentially fatal disease in diabetic and other immunocompromised patients. Cerumen contains defense properties that protect the patient against infection. We tested the hypothesis that patients with diabetes mellitus have abnormalities in their cerumen that affect the environment of their external auditory canals and may predispose them to malignant externa otitis.

Contact hypersensitivity in patients with chronic otitis externa

Thirty-seven patients with chronic otitis externa were investigated for contact hypersensitivity to 49 agents using standardized patch testing. Positive reactions were found in 22 (58%) patients. This incidence is higher than the 40% found in the only previous similar study and is within the range of 32-72% found in patients with contact dermatitis. The average age of subjects showing sensitivity was 56.7 years compared with 34.9 years for those with negative tests. This significant age difference suggests that contact hypersensitivity is not an aetiological factor in the younger patient. There was no significant difference in the duration of otitis externa between those with positive and negative tests. This feature has not been previously examined or reported. Neomycin was the commonest sensitizing agent, sensitization occurring in 12 (32%) patients.

Necrotizing otitis externa due to Aspergillus in an immunocompetent patient

An 85-year-old, nondiabetic man is described with necrotizing (malignant) otitis externa. The patient developed facial nerve paralysis in the presence of a progressive cellulitis and chondritis of the external auditory meatus. Destruction of the bony meatus and mastoid and obliteration of normal soft-tissue planes at the skull base were documented by computed tomographic scans. Aspergillus fumigatus was isolated from the external meatus and deep tissue specimens. Fungal invasion of bone and soft tissue was confirmed histopathologically. Pseudomonas aeruginosa was never isolated. This case is unusual from both the standpoint of etiology and host susceptibility in that the patient had no apparent underlying disease. Amphotericin B and rifampin therapy following radical mastoidectomy halted the progression of disease. Finally, this case illustrates the pitfalls of empiric antibacterial therapy for necrotizing otitis externa without cultural confirmation of the etiologic agent.

Immunologic aspects of otologic disease: an overview

The immunologic explosion has now reached the field of otology. By having better techniques to measure the changes at cellular and molecular levels, it is now possible to devise experiments to show morphologic anatomic changes as well as functional changes. The demonstration in 1980 (M.S.) that tympanosclerosis could be induced immunologically represents a concrete advancement in immunologic thinking in conceptualization of otologic disease. In 1974, one of the authors (M.S.) published work dealing with the treatment of vasculitis of immunologic origin for sudden hearing loss. This was aimed at inhibiting the complement cascade from starting its destructive action. Recently, the immunologic challenge in animals demonstrated by changes in the inner ear was shown by one of the authors (T.J.Y.). Such changes were compatible with labyrinthine hydrops, or Meniere's disease, otosclerosis, and sensorineural hearing loss and vestibular dysfunction.

Malignant external otitis and polymorphonuclear leukocyte migration impairment. Improvement with ascorbic acid

Malignant external otitis (MEO) is a rare disease due to a Pseudomonas infection of the external ear occurring in an elderly patient with uncontrolled diabetes mellitus. Its high mortality raises the question of an alteration of the defense mechanisms of the body. A 58-year-old man was affected with MEO, and after several months of unsuccessful treatment, a study of the function of his polymorphonuclear neutrophil leukocytes (PMNs) revealed a defect of the migration capability. Ascorbic acid (vitamin C) was proved in vitro to be able to improve the results of the migration test. The patient was treated for one month with ascorbic acid and, parallel to the normalization of the chemotaxis test results, the ear lesions healed. The mechanism of such an alteration of the PMN function, implying several factors (the active infection, old age, and diabetes mellitus), is still unclear. Nevertheless, it is certainly important to test the PMN function in patients with MEO and treat them with immunomodulators.

Impairment of cellular immunity in patients with malignant external otitis

Immunological studies were performed on 4 elderly diabetic patients with Malignant External Otitis caused by Pseudomonas aeruginosa. Impairment of cellular immunity was found. Skin tests for delayed hypersensitivity to PPD, SK-SD and Mumps antigen were negative and stimulation rates of peripheral blood lymphocytes by PHA, Con-A and PWM were depressed in all 4 patients. Serum immunoglobulins and complement levels were normal except in one case in which paraprotein IgG was found. Peripheral blood lymphoid cell markers and the neutrophil nitroblue tetrazolium (NBT) test were within normal limits in the 2 patients tested. These results indicate that cellular immune deficiency predisposes to the development of Malignant External Otitis in elderly diabetic patients.