The spectrum of inflammatory cell response to dimethyl sulfoxide

Dimethyl sulfoxide (DMSO), depending upon the concentration and mode of application to the skin, can induce either a non-immunological immediate contact urticaria or an irritant reaction. The dermal cellular infiltrate after open application of varying concentrations of DMSO has been studied in an experimental guinea pig model. The composition of the dermal cellular infiltrate showed a spectrum dependent on the concentration and number of applications of DMSO. The immediate reaction infiltrate 3 h after application of 100% DMSO consisted of 50% granulocytes, basophils being predominant. On the other hand, 12% DMSO applied 3 x daily for 3 days (cumulative insult) caused histologically a cellular reaction in which 80% of the infiltrate consisted of mononuclear cells. The present findings are compared to the microscopic findings in 3 other cutaneous reactions previously studied in this animal model, namely, the Type I immediate hypersensitivity reaction, the Type IV delayed hypersensitivity reaction, and the irritant reaction. Differing cellular infiltrate patterns are discernible at the same time points. The study illustrates the spectrum of inflammatory reactions seen in the skin and provides background information for future clinical studies, for instance, on the role of the basophil granulocyte in immediate contact reactions.     

The influence on the dermal cellular infiltrate of topical steroid applications and vehicles in guinea pig skin: normal skin, allergic and toxic reactions

The mechanisms of the anti-inflammatory effects of carticosteroids are uncertain but could be explained by an influence on infiltrating leukocytes. Our method for the qualitative and quantitative investigation of the dermal cellular infiltrate makes it possible to study the effects of topically applied corticosteroid preparations and vehicles on the infiltrating leukocytes of normal skin, allergic and toxic reactions in guinea pig skin. Ointment and cream vehicles as well as corticosteroid cream and ointment preparations often caused erythema and increased mononuclear infiltrate after only short periods of application (24-72 h). The strongest steroid ointment gave the most marked macroscopic response and propylene glycol preparations the most marked cellular response. In both toxic and allergic reactions, application of steroid preparations after the provocation gave no beneficial result cither macroscopically or microscopically. Macroscopic scores were worsened by cream and ointment preparations. Although steroid solutions had no beneficial effect, they caused no detrimental effect. The guinea pig seems to be extremely sensitive to irritants and has not proved to be a suitable model for this approach to the study of the efficacy of topically applied steroids.     

Morphea-like tattoo reaction

Tattoo reactions are histologically diverse. In general, dermal changes predominate, although epidermal changes such as acanthosis or spongiosis can also be seen. The chronic inflammatory cell infiltrate can be nodular, lichenoid, or granulomatous. Occasionally, the dermal infiltrate may be so dense as to suggest a diagnosis of cutaneous lymphoma. We report an unusual tattoo reaction that mimicked morphea histologically.     

Sweet-like reaction due to arthropod bites: a histopathologic pitfall

The histopathology of arthropod bite reactions is classically described as "dermal edema" with superficial and middle to deep dermal inflammation in a perivascular and wedge-shaped distribution. The composition of the infiltrate may vary, but a characteristic feature is the presence of prominent eosinophils between collagen bundles. Sweet syndrome, also known as acute febrile neutrophilic dermatosis, is characterized by dermal edema and a dense neutrophilic infiltrate, associated with a constellation of clinical and biological signs. We describe herein 2 cases of arthropod bite reactions with impressive clinical lesions and histopathological findings reminiscent of Sweet syndrome. However, the patients were lacking other criteria for Sweet syndrome and were diagnosed as Sweet-like reaction to arthropod bites. Pathologists should be careful in rendering a diagnosis of neutrophilic dermatosis, which requires clinicopathological correlation, and should consider arthropod bite reactions in the differential diagnosis.     

Lymphomatoid papulosis in children: experience of five cases and the treatment efficacy of methotrexate

We present a case series of childhood lymphomatoid papulosis (LyP), an entity which is commonly misdiagnosed and poorly described in the paediatric dermatology literature. Clinically and histologically, the features of LyP in children can mimic insect bite reactions, with prominent dermal neutrophils and eosinophils. However, CD30 immunohistochemical staining of atypical lymphocytes within a mixed inflammatory infiltrate should point to the diagnosis of LyP. There is no consensus to guide management of childhood LyP due to its rarity and largely unknown natural course. We discuss our experience with LyP in five children and the use of methotrexate to induce rapid resolution of persistent lesions and to reduce recurrences in two children. Although none of our cases have experienced malignant transformation to date, life-long monitoring is advocated.     

Post-kala-azar dermal leishmaniasis: A light and electron microscopic study of 18 cases

Post-kala-azar dermal leishmaniasis (PKDL) is caused by the protozoan parasite, Leishmania donovani , and is seen in patients with history of having been treated earlier for the visceral disease form, kala-azar, caused by the same organism. The findings from 18 patients with PKDL are described in this study. The skin manifestations ranged from hypopigmented macules to infiltrated plaques and nodules. Histopathologic examination revealed a cellular infiltrate of lymphocytes, plasma cells, and macrophages. The macrophages were scattered amidst the infiltrate without any localization. In hypopigmented lesions, the infiltrate was confined to the perivascular region in the superficial dermis and was composed mainly of lymphocytes and few plasma cells. In the nodular lesions, the infiltrate occupied the entire thickness of the dermis. Leishman-Donovan bodies were scarce and identified in 16 cases after a prolonged search of Weigert's iron hematoxylin-stained sections. In 2 cases, Leishman-Donovan bodies were not demonstrable. Electronmicroscopic study revealed parasitized macrophages which showed no structural evidence of activation despite the active cellular response around them. The fine structure of the parasites in the histiocytes was also well maintained. This unusual tropical dermatosis is a unique example of change in organotropism of a parasite associated with a change in the host response.     

Eosinophilic cellulitislike reaction to subcutaneous etanercept injection

BACKGROUND: Injection site reactions are well recognized in patients treated with etanercept. Previous reports describe histologic findings of a cell-mediated T(H)1 reaction, with CD8+ T cells composing the majority of the dermal infiltrate. OBSERVATIONS: A pruritic, erythematous, edematous patch occurred on the right thigh of a 57-year-old white woman treated for rheumatoid arthritis within 12 to 24 hours after her second dose of subcutaneous etanercept. The patient had a similar reaction to adalimumab injection 2 weeks prior to presentation. While benzyl alcohol is present in the etanercept preparation, and mannitol in both drugs, dermal injection revealed no reaction to these additives. Biopsy specimens from the etanercept injection site demonstrated papillary dermal edema accompanied by a brisk polymorphous infiltrate with a predominance of eosinophils and scattered flame figures. CONCLUSIONS: Histologic features of eosinophilic cellulitis as a response to etanercept have not been reported to date. Although most injection site reactions contain T cells and represent a T(H)1 immune response, the findings we report suggest a T(H)2-mediated phenomenon.     

Hyperkeratosis lenticularis perstans (Flegel's disease). In situ characterization of T cell subsets and Langerhans' cells

We report a patient with hyperkeratosis lenticularis perstans (HLP) manifesting as multiple reddish-brown hyperkeratotic papules on the lower extremities. Typical histologic features of HLP include hyperkeratosis, thinning or absence of the granular layer and a band-like infiltrate in the upper dermis underlying an atrophic epidermis. In order to determine the cellular composition of the infiltrate, skin biopsy specimens were studied immunohistochemically using a series of commercially available monoclonal antibodies. The dermal infiltrate consists predominantly of helper/inducer T cells (Leu-4+, Leu-3a+). Suppressor/cytotoxic T cells (Leu-2a+) were fewer at the periphery of the infiltrate. The majority of T cells were activated as they expressed HLA-DR-antigen. Large numbers of Leu-6+ Langerhans' cells were observed at the dermo-epidermal interface. Few natural killer cells (Leu-11b+) were noted within the dermal infiltrate. These findings support the hypothesis than an active cellular immune reaction involving the epidermis is of pathogenic importance for HLP.     

Common pathogenetic pathways in allergic and irritant contact dermatitis.

Despite their different pathogeneses, allergic and irritant contact dermatitis show a remarkable similarity with respect to clinical appearance, histology, and immunohistology. To further analyze this apparent contradiction, our study was designed to meticulously compare cellular infiltrates in irritant and allergic patch-test reactions by immunostaining with a broad panel of monoclonal antibodies. For this purpose, skin biopsies from allergic and irritant patch-test reactions of similar inflammatory degree were obtained from the same probands. We found that after 72 h both types of reaction were characterized by an identical dermal infiltrate consisting mainly of memory T cells, many of which were activated, and macrophages. Dermal and epidermal Langerhans cell density and HLA--DR expression of keratinocytes were also virtually identical. Our results show that antigen recognition by specific memory T cells as well as irritants can finally induce the same pattern of inflammation, including activation of T cells obviously independent of exogenous antigen.     

Lymphomatoid papulosis. Histologic and immunohistochemical studies in a patient with a scaly pigmented eruption

A patient with lymphomatoid papulosis type A showed a peculiar, scaly pigmented eruption on the broad skin areas as well as papulonodular lesions. Large atypical cells characteristic of the infiltrate of the disease were observed not only in the dermal infiltrate of papular lesions, but also in the perivascular infiltrate of the scaly pigmented lesions, indicating that the latter was one of the skin manifestations of lymphomatoid papulosis. Immunohistochemical studies showed that these atypical cells expressed Ki-1 and cellular activation-associated antigens such as HLA-DR, Tac, and T9, but were not reactive with T-cell specific antibodies Leu-1, Leu-3a, and Leu-2a.     

Atopic dermatitis: a histologic and radioautographic study (after 3H-thymidine labelling) of epidermal and dermal lesions (author's transl)]

Skin lesions of atopic dermatitis (A. D.) have been studied histologically and radioautographically after in vitro incorporation of tritiated thymidine. The histopathologic aspects of epidermis in the different types of skin lesions are reviewed. The dermal infiltrate is mononuclear and not very abundant in all types of lesions. An enlargement of the epidermal proliferative compartment has been noticed. Labelled cells are distributed as follows (mean +/- standard deviation) : 46 +/- p. 100 in the basal layer; 37 +/- 6 p. 100 in the epibasal layer; 16 +/- 7 p. 100 in the upper layers. The basal and epidermal labelling indices have been found significantly increased in exudative and lichenified lesions as compared to xerotic areas and normal epidermis. The labelling index of the "round" cell infiltrate in the dermis was significantly higher than in irritant patch test reactions (p less than 0.001) but significantly lower than in allergic positive patch test reactions (p less than 0.001). This increased cell proliferation in the dermal infiltrate does not allow definite conclusions about immunopathogenesis of the disease: indeed, a large number of mediators, involved in the inflammatory reactions of A. D. lesions, can modulate cell proliferation.     

Immunopathology of toxic epidermal necrolysis. Keratinocytes, HLA-DR expression, Langerhans cells, and mononuclear cells: an immunopathologic study of five cases.

BACKGROUND--Toxic epidermal necrolysis is a potentially severe mucocutaneous affliction whose cause is usually drug related. To further characterize the nature of the dermal mononuclear infiltrate as well as the epidermal alterations observed by standard microscopy, we studied five cases of toxic epidermal necrolysis using labeled monoclonal antibodies. RESULTS--On clinically involved areas of skin, the following occurs: (1) the dermal infiltrate is composed mainly of activated T lymphocytes, with a predominant helper phenotype; (2) the number of Langerhans cells is decreased; and (3) keratinocytes express HLA-DR molecules, normally absent on their surface. CONCLUSIONS--These findings, although not specific, are consistent with an immune cellular reaction, but they could also be linked to an inflammatory reaction initiated by epidermal damages whatever its primary mechanism.     

Immunocompetent cells of fixed drug eruption

The positive provocation test reactions of the skin of six patients with fixed drug eruption (FDE) were studied from timed skin biopsies taken between 2 hours and 9 days after the appearance of FDE. Monoclonal antibodies to the following immunocompetent cell surface epitopes were used: T3, T4, T6, T8, T9, M1, Ia1, Drc, Leu7 and B cell. The dermal infiltrate comprised 60-80% of T lymphocytes at all the times studied. Cells with T4 and T8 epitopes were displayed in similar numbers. A transient decrease in the number of T6+ cells of the epidermis could be detected with a simultaneous and also transient increase of the T6+ cells in the dermis, which suggests a possible traffic of Langerhans' cells from the epidermis to the dermis. The epidermal Ia1+ cells showed changes similar to but less marked than the T6+ cells. The number of the dermal Ia1+ cells increased continuously. In the late biopsies these Ia1+ cells comprised up to 90% of the infiltrating cells. Except for the finding of a reduction of T6+ and Ia1+ epidermal cells, the cellular kinetics of FDE are similar to those seen in both cutaneous immunological and irritant reactions.     

An immunopathological study of herpes-associated erythema multiforme

Any pathogenetic mechanism proposed for erythema multiforme (EM) must account for the prominent mononuclear cell infiltrate in the skin lesions. The purpose of this study was to characterize immunopathologically, with monoclonal antibodies to human leukocyte antigens, the inflammatory cells in early target lesions of recurrent herpes-associated EM. Cryostat sections of snap-frozen skin biopsies were studied by the avidin-biotin immunoperoxidase technique with use of the following monoclonal antibodies: anti-HLA-DR, anti-Leu M5, anti-Leu 4 + 5b, anti-Leu 3a + 3b, anti-Leu 2a, anti-Leu 14, and anti-Leu 6. The dermal mononuclear inflammatory infiltrate in the EM biopsies consisted of monocyte-macrophages and T-lymphocytes, with both helper and suppressor T cells present. Both the dermal inflammatory infiltrate and the overlying keratinocytes were strongly HLA-DR positive. No definite alteration of Langerhans cell number or distribution was noted. These findings are consistent with the characteristics seen in cell-mediated immune reactions in the skin and point to this as a likely immune mechanism for the tissue damage of EM.     

Indeterminate leprosy: a clinical and histopathological evaluation

27 histologically confirmed indeterminate leprosy cases were evaluated clinically and histopathologically at the SLR & TC, Karigiri, South India in 1985. The main clinical finding was a single or multiple (up to 3) patches. This was found in 25 (92%) of 27 cases. 2 cases only showed an area of anaesthesia without any skin lesion. Loss of sensation was present in 22 cases (81%). Histologically all cases (100%) showed lymphohistiocytic infiltration around the dermal structures and around/in the dermal nerves. AF bacilli were found in 17 cases (63%). They were detected most commonly in cellular infiltrate in the dermis (7 cases, 26%) and secondly in the dermal nerves (5 cases, 14%). Careful search and deeper sections increased the chance of detecting bacilli. Criteria for histological diagnosis were also discussed.     

The effect of grenz rays on irritant skin reactions in man

To investigate the effect of grenz rays on irritant contact reactions, eleven healthy volunteers were studied. They were given 3 Gy of grenz rays, once a week for 3 weeks, to a defined area of the back. Twenty-four hours after the last treatment, serial dilution sodium lauryl sulphate patch tests were applied both on the grenz ray treated area and on the untreated control skin. Biopsy specimens were taken from the irritant reactions both from the grenz ray treated area and from the control area and different cell populations in dermis and epidermis were identified by monoclonal antibodies (Leu 2, 3, 4, 7, Leu M1, B1, OKT6). In the grenz ray treated epidermis there was a pronounced reduction of OKT6-positive cells but the composition of the dermal cellular infiltrate did not differ between control and grenz ray treated skin. The assessment of the patch test reactions did reveal a tendency towards weaker reactions in the grenz ray pre-treated skin but this difference was not statistically significant. It is concluded that grenz rays do not have a marked effect on the elicitation of irritant reactions.     

A scanning microscopic clue to the diagnosis of arthropod assault reaction: alteration of interstitial tissue is more common than a wedge-shaped inflammatory infiltrate

Background:  A scanning microscopic clue to the diagnosis of arthropod assault reactions is a wedge-shaped inflammatory infiltrate. However, to describe an inflammatory infiltrate as wedge-shaped or not involves a high degree of subjectivity.
Methods:  We studied hematoxylin and eosin-stained sections of 137 biopsies of arthropod assault reactions for epidermal and dermal changes and for the composition, density and depth of the inflammatory infiltrate.
Results:  We found a wedge-shaped inflammatory component in only 10.2% of the cases. A much more common feature is an alteration of the interstitial tissue present in 85.4% of the biopsies. It consisted of a narrowing of the spaces between the collagen bundles, which was readily observable on scanning magnification. On higher magnification, a loosely textured basophilic material was often noted within the dermis.
Conclusions:  The hitherto often emphasized wedge-shaped configuration of the inflammatory component of arthropod assault reactions is not of great diagnostic value. The altered interstitial tissue is easily recognizable by its diminished interstitial spaces at low power magnification and can serve as a scanning magnification clue to the diagnosis of arthropod assault reactions.     

Acetone has anti-inflammatory effects on experimental contact reactions

The effects of a topically applied corticosteroid and its acetone vehicle on experimental allergic, toxic and irritant reactions are presented. The corticosteroid budesonide in acetone or acetone alone was applied to reactions immediately after and at different time intervals within the 1st h after provocation. Classical naked eye observation was performed and the dermal cellular infiltrate was differentiated and counted using a previously well-characterized method. "Treatment", whether with the steroid in acetone or acetone alone, had anti-inflammatory effects. For all reaction types, erythema and oedema diminished and a significant decrease in mononuclear cells was seen, when application occurred within the first 5 min after provocation. The effects were most marked for the toxic reaction to croton oil, the steroid and the vehicle being anti-inflammatory to the same extent. Application up to 60 min after provocation had anti-inflammatory effects for this reaction type. The mechanisms of acetone's anti-inflammatory effects are at present unclear. One possible explanation is that intercellular lipid organisation and, by extension, cellular membrane lipid organisation, are altered, influencing membrane receptor function. Possible anti-inflammatory effects of acetone should be considered in experimental and perhaps even clinical situations. Further investigation of the therapeutic possibilities of the finding seems warranted.     

Enfuvirtide injection site reactions: a clinical and histopathological appraisal

Background/Objectives: Enfuvirtide was the first of a new class of antiretroviral agents termed ‘fusion inhibitors’ used for the treatment of HIV‐1 infection. Enfuvirtide is administered subcutaneously and injection site reactions (ISR) are commonplace (98%). The aim of this study was to analyse in detail the histopathological changes associated with striking ISR seen in four patients. Methods: Biopsies were obtained at various times post‐injection and were reviewed histologically. The changes in epidermal, dermal and subcutaneous connective tissue and the presence and nature of the inflammatory cellular infiltrate were noted. An immunohistochemical assessment was undertaken. Results: All biopsy specimens demonstrated striking changes in the dermal connective tissue. Alteration in collagen was the most prominent feature and resembled a morphoea/scleroderma‐like process. These changes persisted well beyond cessation of enfuvirtide (>1 year). The relative populations of dermal dendritic cells (DDC) (types 1 (Factor XIIIa) and 2 (CD34+)) were analysed and a reciprocal relationship between DDC subpopulations was observed akin to that observed in other sclerosing and fibrosing conditions. Conclusion: This study details histopathological changes associated with enfuvirtide ISR. We postulate that changes in DDC populations may contribute to the pathogenesis of the sclerotic process observed with enfuvirtide ISR.     

Immunophenotyping of the eczematous flare-up reaction in a nickel-sensitive subject

An eczematous flare-up reaction, occurring at a previously involved site, which followed oral challenge with 5.6 mg of nickel in a 29-year-old nickel-sensitive woman, was biopsied and studied by immunohistochemistry. The cellular infiltrate in the dermis and epidermis at 8 days was predominantly of Leu 3a phenotype (helper/inducer T lymphocytes), with smaller numbers of Leu-2a-reactive (suppressor/cytotoxic) T lymphocytes. Many infiltrating cells were DR-positive. No increase in epidermal Leu-6-positive Langerhans cells was seen but Leu-6-reactive cells were noted in the dermal infiltrate. Keratinocytes showed some expression of class II antigen (mainly DR). In comparison with the 48-hour allergic patch test reaction, the eczematous flare-up site showed no increase in epidermal Langerhans cell numbers nor infiltration with macrophages, but the responses were similar since both showed a superficial T cell reaction in the skin.