Herbert B. Allen

The Presence and Impact of Biofilm-Producing Staphylococci in Atopic Dermatitis

IMPORTANCE Atopic dermatitis (AD) is thought to be a double-hit phenomenon with an unknown environmental component and a genetic abnormality likely centered on the filaggrin gene. Biologically, the presence of Staphylococcus aureus in AD was reported more than 2 decades ago, but the relationship to AD has been elusive. OBJECTIVE To explore the bacteria that produce the biofilms in the lesions of AD and the response of the innate immune system to these biofilm occlusions of the sweat ducts by specifically evaluating Toll-like receptor 2. DESIGN, SETTING, AND PARTICIPANTS University hospital dermatologic clinic study involving the environmental component related to the characterization, correlation, and impact of staphylococci and their biofilms in AD. We processed routine skin swabs from lesional and nonlesional skin from 40 patients with AD and performed scrapings and biopsies. We also obtained 20 samples from controls (10 inflamed skin samples and 10 normal skin samples). EXPOSURES Gram staining, bright-field microscopy, hematoxylin and eosin, periodic acid-Schiff, Congo red, and light microscopy. MAIN OUTCOMES AND MEASURES Association of staphylococcal biofilms with AD pathogenesis. RESULTS All AD-affected samples contained multidrug-resistant staphylococci, with S aureus (42.0%) and Staphylococcus epidermidis (20.0%) as the predominant species. All isolates were positive for extracellular polysaccharide and biofilm (85.0% strong biofilm producers and 15.0% moderately to weakly positive). Polymerase chain reaction revealed the biofilm-mediating icaD (93.0%) and aap (12.5%) genes in the isolates (some contained both). We also examined tissues for microbial identification, extracellular biomass formation, biofilm formation, and staphylococcal biofilm in skin tissues. Occlusion of sweat ducts with periodic acid-Schiff-positive and Congo red-positive material was noted on microscopic tissue examination. Toll-like receptor 2 was shown to be activated in AD lesional skin (immediately proximal to the sweat ducts), which likely led to the initiation of proteinase-activated receptor 2-mediated pruritus and MyD88-mediated spongiosis. CONCLUSIONS AND RELEVANCE Biofilm formation by AD-associated staphylococci almost certainly plays a major role in the occlusion of sweat ducts and leads to inflammation and pruritus. We believe the environmental hit in AD relates to staphylococci and their biofilms, which occlude sweat ducts.

Alzheimers Disease: A Novel Hypothesis Integrating Spirochetes, Biofilm, and the Immune System

In the light of recent studies showing the presence of spirochetes in the brains of Alzheimer’s disease (AD) patients, we have studied (post mortem) the hippocampus region in the brains of similarly affected AD patients utilizing both pathology and immunohistochemistry. Our findings demonstrate that the plaques, which are characteristically found in AD brains, reveal the presence of biofilms. These biofilms are undoubtedly made by the spirochetes present there; further, we have also found that the biofilms co-localize with the β amyloid that is a signature finding in the disease. Also, we have shown activation of Toll-like receptor 2 in the same areas. We postulate this is related to the disease because this innate immune system molecule cannot penetrate the biofilm to destroy the spirochetes present there, so, inasmuch as it is activated, it destroys the surrounding tissue instead. We compare this destruction to that which is caused by activation of the adaptive immune system, which leads to much more severe devastation, much more rapidly.

Alzheimer's Disease: Assessing the Role of Spirochetes, Biofilms, the Immune System, and Amyloid-β with Regard to Potential Treatment and Prevention.

Alzheimer’s disease (AD) is an infectious disease caused by spirochetes, and these spirochetes form biofilms, which attract the innate immune system. The innate immune system first responder, Toll-like receptor 2, generates both NF-κB and TNF-α which try to kill the spirochetes in the biofilm, but cannot penetrate the “slime”. NF-κB is also responsible for the generation of amyloid-β (Aβ) which itself is anti-microbial. Aβ cannot penetrate the biofilm either, and its accumulation leads to destruction of the cerebral neurocircuitry. Treatment with penicillin (as in tertiary syphilis, the comparator to AD) is outlined; a biofilm dispersing agent may need to be added to the protocol.

Lichenoid and other clinical presentations of atopic dermatitis in an inner city practice.

Atopic dermatitis (AD) has many different clinical presentations. In our inner city practice, we have observed a variant of AD in our heavily pigmented patients that we have termed lichen planus-like atopic dermatitis because of its clinical similarity to lichen planus. Clinically, this variant may be distinguished by the presence on extensor surfaces and a more rapid response to treatment. Histologically, in lichen planus-like AD, a spongiotic dermatitis is present; further, there is no lichenoid dermatitis evident. We compare this presentation with the others seen over an eight-month interval in our practice. We report on a lichen planus-like variant of atopic dermatitis in our African American patients. A limitation to this report is the relatively small sample size. Facial/extensor is the most common presentation of atopic dermatitis in our predominantly minority clinic.

Lichen planus-like atopic dermatitis: expanding the differential diagnosis of spongiotic dermatitis.

Spongiotic dermatitis represents a commonly encountered histopathological pattern seen by dermatopathologists. The differential diagnosis of lymphocyte predominant acute spongiotic dermatitis typically entails atopic dermatitis (AD), contact dermatitis, nummular dermatitis, pityriasis rosea and seborrheic dermatitis. Recently, our group has characterized a distinct subtype of spongiotic dermatitis occurring exclusively in heavily pigmented patients. Clinically, lesions of this subtype are nearly indistinguishable from lichen planus. However, the histology is contradistinctive to classic lichen planus. The purpose of this report is to raise awareness among dermatopathologists of this variant as a possible diagnosis in spongiotic dermatitis specimens submitted as lichen planus.

Autoimmune Diseases of the Innate and Adaptive Immune System including Atopic Dermatitis, Psoriasis, Chronic Arthritis, Lyme Disease, and Alzheimers Disease

In atopic dermatitis, we have recently shown the innate immune system is activated by biofilm-forming staphylococci that occlude sweat ducts. Toll-like receptor 2 (TLR 2) is activated and moves from its epidermal control location in the basal zone to the proximal stratum corneum (surrounding the occluded duct). There it likely initiates the MyD88 and the PAR 2 pathways in an effort to inactivate the staphylococci; these efforts are fruitless because of the biofilms and lead to the prime pathological finding of spongiosis and to the prime symptom of pruritus which leads to the disease. If the pruritus is intense enough to cause excoriations severe enough to disrupt the epidermis, the involvement of the dermis likely causes the activation of the adaptive immune system leading to the documented appearance of IL 31, another even more potent pruritogen. We have also shown that the innate system is involved in psoriasis, again with TLR 2. This time it was present in the dilated upper dermal capillaries; TLR 2 has been shown to lead to TNFa, IL 12/23, and IL 17 which have all been shown to be involved in the production of psoriatic lesions. In this instance, the streptococcus is most likely the organism involved; it is not recoverable because it internalizes or makes biofilms, so TLR 2 instead of combating the bacterium attacks host cells. Anti-streptococcal IgG is markedly elevated in plaque psoriasis in one half the patients; it is of interest to postulate these patients were those who would develop the systemic findings of arthritis, uveitis, and the metabolic syndrome which develop in 40% of patients. In chronic arthritis, Lyme disease, and Alzheimer’s disease where the disease has been shown to be caused by Borrelia and dental spirochetes, TLR 2 is activated because of the presence of the microbes and their biofilms and leads to the chronic course noted in osteoarthritis, Lyme neuroborreliosis and Alzheimer’s disease. When the adaptive immune system is involved, as in rheumatoid arthritis and after a stroke, it is curious that the disease occurs more rapidly and is much more destructive.

The Oldest New Finding in Atopic Dermatitis: Subclinical Miliaria as an Origin

IMPORTANCE In 1947, Sulzberger and colleagues published a micrograph of a blocked acrosyringium in a patient with atopic dermatitis (AD), believing that it had a large role in the disease process. Lacking appropriate probes, they could not confirm the finding. OBJECTIVE To confirm the observations by Sulzberger et al on the blockage of sweat ducts in AD in pathologic specimens. DESIGN AND SETTING Biopsy specimens diagnostic of various inflammatory diseases and with a secondary differential diagnosis of eczema were evaluated at an academic medical center. EXPOSURES Evidence of ductal obstruction in each specimen was examined following staining with hematoxylin-eosin, periodic acid-Schiff, and Gram stain. MAIN OUTCOMES AND MEASURES Comparison of biopsy specimens with control specimens and additional controls consisting of noninflamed skin. RESULTS Using 36 biopsy specimens, this study confirmed the observations by Sulzberger et al on the blockage of sweat ducts in AD. Blocked acrosyringia were noted in each specimen on routine staining with hematoxylin-eosin. The study also confirmed the findings by earlier investigators about the blockage of sweat ducts in miliaria, showing eosinophilic material in the ducts that was positive for periodic acid-Schiff. Previous researchers also observed bacteria in the blockages, and this study demonstrated the same findings in AD, rather than miliaria. CONCLUSION AND RELEVANCE Subclinical miliaria may be the earliest change in AD and likely initiates the process that causes intense pruritus.

Alzheimer's disease: a novel hypothesis for the development and the subsequent role of beta amyloid

Spirochetes, biofilms, innate immune system activity have all been recently found in the brains of Alzheimers disease patients. The mechanism and actions of those entities in producing the disease were postulated in those studies. The production and role of beta amyloid were not included in the discussion; we hypothesize herein how the development of that molecule occurs as a result of the Toll-like receptor 2 activation leading not only to TNFα, but also NFκB which themselves have been previously shown to induce the secretases necessary to cleave the amyloid precursor protein. This leads directly to beta amyloid. The beta amyloid (Aβ) has been shown to be antimicrobial, and its presence on and around the hippocampal plaques (the pathological hallmark of Alzheimers disease) has been demonstrated. It becomes apparent that the Aβ tries to kill the spirochetes but cannot penetrate the biofilm. Its buildup then interrupts and destroys the neurocircuitry of the brains.

Psoriasis: A Sequela of Streptococcal Infection Similar to Acute RheumaticFever

We propose that psoriasis is a sequela of streptococcal infection similar to acute rheumatic fever (ARF). This hypothesis arises from many different lines of evidence: a markedly elevated serum anti-streptococcal antibody is present in plaque psoriasis. However, cultures are routinely negative in psoriasis because the Group A Streptococcus pyogenes “hides” inside cells and inside biofilms and is thereby unculturable. The activation of either arm of the immune system is likely related to whether internalization or biofilm formation is predominant. With internalization, we postulate it is the adaptive immune system and with biofilm formation, the innate system. Lastly, prolonged treatment with anti-GAS antibiotics is effective in psoriasis as in ARF.

A novel finding in atopic dermatitis: film-producing Staphylococcus epidermidis as an etiology

Recently, we surveyed our inner city practice regarding the forms of atopic dermatitis we see here, including facial-extensor, flexural, nummular, lichen planus-like (seen only in darkly pigmented skin), and pityriasis alba. Many factors triggering this disease have been proposed, such as xerosis and sweating, but factors causing pruritus, especially in flexural eczema, have not been elucidated. We believe the patient presented herein shows findings pointing to an explanation for such pruritus. We believe that subclinical miliaria caused by film-producing Staphylococcus epidermidis blocks the eccrine ducts and causes pruritus similar to that seen in overt miliaria rubra. A 19-year-old Caucasian woman with a family history of maternal asthma presented with a very pruritic, pink– red, papulovesicular eruption on the antecubital and popliteal fossas. She habitually bathed twice daily with a body wash and did not use a moisturizer. We diagnosed atopic dermatitis and prescribed twice-daily application of a midpotency corticosteroid cream; skin care advice consisted of using a moisturizer daily and decreasing the frequency of bathing. We recommended that she use a milder soap and restrict its use to certain body parts. At her three-week follow-up visit, the pruritus had abated and the rash had cleared. At the follow-up visit, a skin scraping was taken from the right antecubital fossa in a manner similar to a potassium hydroxide preparation for fungus. The sample was cultured for bacteria and was examined under confocal microscopy. The culture showed normal skin flora (predominantly S. epidermidis) without any Staphylococcus aureus. Cocci with biofilms similar to those of film-producing S. epidermidis were noted on confocal microscopy and appeared as a syncytium as opposed to ordinary single bacterial cells (Fig. 1). This patient demonstrated typical flexural atopic dermatitis that responded well to treatment. The skin scraping showing film-producing S. epidermidis is of interest. We believe subclinical miliaria causes the itching in this form of eczema, which has been termed ‘‘the itch that