Rickettsialpox-like illness in a traveler.

A patient presented after a trip to South Africa with a febrile illness and rash that was consistent with either rickettsialpox or mild boutonneuse fever. The clinical, laboratory, and geographic overlap of these diseases makes differentiation difficult in certain situations. Several different rickettsial infections may cause an eschar and a rash that may be papulovesicular. From a clinical perspective, distinguishing these diseases is not critically important as long as therapy with tetracycline is implemented. More precise identification of the etiologic agent could be required in certain military situations because the preventive measures employed for some of these diseases may be significantly different.

Acquired digital fibrokeratoma.

Acquired digital fibrokeratomas are benign growths that usually occur on the fingers. These growths have a characteristic clinical and histopathologic appearance and may be easily recognized and treated by family physicians. It is important not to confuse these lesions with other common, possibly malignant, clinical entities. Treatment involves shave excision under local anesthesia.

Vertical and transverse sections of alopecia biopsy specimens: combining the two to maximize diagnostic yield.

BACKGROUND: Traditional vertical sections of scalp biopsy specimens contain few hair follicles. For this reason transverse sections of scalp biopsy specimens have been advocated. Both methods have advantages and disadvantages. We have developed a simple method that we believe offers the best of both methods. OBJECTIVE: Our purpose was to assess the impact of combining vertical and transverse sections of scalp biopsy specimens. METHODS: Two 4 mm punch biopsies are performed. One specimen is bisected vertically: half for hematoxylin-eosin (H-E) staining, half for direct immunofluorescence. The second specimen is bisected transversely and submitted for H-E. The three pieces of tissue for H-E staining are embedded in a single cassette. RESULTS: Because a biopsy specimen for direct immunofluorescence is commonly obtained in cases of alopecia, our method does not add a surgical procedure. All three pieces of tissue for H-E staining are embedded in a single paraffin block. Therefore the cost of histologic interpretation is not increased. Our diagnostic yield improved. Transverse sections were superior in cases of lupus erythematosus and lichen planopilaris with focal follicular involvement. Features of the follicular degeneration syndrome were also best demonstrated in transverse sections. Interface changes, lupus panniculitis, miniaturized hairs, and trichomalacia were better demonstrated in vertical sections. CONCLUSION: Our method exploits the advantages of both vertical and transverse sections and improves diagnostic yield without increasing cost.

Inhibition of Langerhans cell antigen-presenting function by IL-10. A role for IL-10 in induction of tolerance.

IL-10 is a product of activated keratinocytes and is released during the induction phase of contact sensitivity. As IL-10 effects have been described as being mediated by APC, we investigated effects of IL-10 on epidermal Langerhans cells (LC), the resident APC in the epidermis. Initial studies failed to demonstrate effects of IL-10 on MHC class II Ag expression by LC or anti-CD3 mAb- or alloantigen-induced LC-dependent T cell proliferation. However, production of IFN-gamma and IL-2, (but not IL-6) was markedly reduced in these assays. When the soluble-protein Ag specific T cell clones AE7 (Th1) and D10.G4 (Th2) were substituted for unprimed T cells, differential effects of IL-10 on T-cell proliferation were observed. Whereas IL-10-pretreated and untreated LC supported Th2 cell proliferation equally well, IL-10-pretreated LC were essentially unable to induce Th1 cell proliferation in response to native protein or peptide Ag. The inhibitory influence of IL-10 on Th1 cells was observed when fresh or 1 day cultured LC were used; 2- or 3-day cultured LC were affected to a much lesser extent by IL-10 pretreatment. Further, coculture experiments using IL-10-pretreated or untreated LC of a different haplotype suggest that IL-10 negatively regulates a costimulatory signal required for induction of Th1 cell proliferation. To assess whether T cells incubated with Ag and IL-10-pretreated LC were responsive to further stimulation, T cells were rescued after 1 day of coculture with IL-10-pretreated LC and restimulated, either immediately or after 1 to 5 days of rest, with untreated LC in the presence of Ag. T cells incubated with IL-10-pretreated LC were found to be anergic, whereas T cells incubated with untreated LC proliferated normally after further stimulation. However, anergic T cells responded vigorously to IL-2. These data indicate that although IL-10-pretreated LC are effective APC for Th2 cells, they fail to induce Th1 cell proliferation and rather induce clonal anergy in these cells.

An essential role for Langerhans cell-derived IL-1 beta in the initiation of primary immune responses in skin.

Langerhans cells (LC) are Ag-presenting cells required for induction of primary immune responses in skin. After activation by Ag, LC express increased levels of MHC class II Ag, exhibit increased accessory cell activity, and migrate to regional lymph nodes where they stimulate T cells. One of the earliest manifestations of LC activation is the accumulation of increased amounts of IL-1 beta mRNA in LC within 15 min after exposure to contact allergens in vivo. To determine if enhanced IL-1 beta production by LC could be causally linked to epicutaneous sensitization, we injected IL-1 beta intradermally into the ears of BALB/c mice and extracted total epidermal RNA 4 h later. A quantitative reverse transcriptase-polymerase chain reaction technique was used to compare changes in IL-1 alpha, IL-1 beta, macrophage inflammatory protein 2, IL-10, TNF-alpha, and 1-A alpha chain mRNA signals caused by intradermally-injected IL-1 beta to those caused by intradermal IL-1 alpha or TNF alpha, or by topical application of the contact allergen trinitrochlorobenzene (3% TNCB). Intradermal injection of 25 ng IL-1 beta resulted in 5-to 100-fold enhancement of mRNA signals for IL-1 alpha, IL-1 beta, MIP-2, IL-10, TNF alpha, and class II I-A alpha, mimicking the changes caused by allergen. In contrast, injection of equivalent amounts of IL-1 alpha or TNF alpha did not significantly alter the epidermal cytokine pattern. Simulating the effects of topically applied TNCB, intradermally-injected IL-1 beta (but not IL-1 alpha or TNF alpha) also caused enhancement of LC MHC class II expression. In addition, LC derived from IL-1 beta-injected skin were 2 to 3 times more potent accessory cells in an anti-CD3 proliferation assay than LC from IL-1 alpha or sham-injected skin. Finally, injection of hamster anti-mIL-1 beta mAb into the skin prior to TNCB treatment completely prevented sensitization to this allergen, although injections of similar amounts of hamster anti-mIL-1 alpha mAb or PBS were without effect. Taken together, our data indicate that dendritic cell-derived IL-1 beta may be a critical molecule required for initiation of primary immune responses in skin.

Pseudocyst of the auricle associated with trauma.

A pseudocyst of the auricle (benign idiopathic cystic chondromalacia) is an intracartilaginous cystic swelling of the anterior auricle. The cause is uncertain, and most patients deny any history of inflammation or trauma. A patient had antecedent trauma and a fracture in the conchal cartilage; a simple surgical procedure was used to treat this patient.

Frontalis-associated lipoma of the forehead.

We describe a deeply placed lipoma of the forehead. This fatty tumor is usually misdiagnosed initially as an epidermal inclusion cyst. Preoperative recognition allows its proper depth within the tissue, that is, within or just below the frontalis muscle, to be anticipated.

Nail, skin, and scleral pigmentation induced by minocycline.

Minocycline-induced cutaneous and nail bed discoloration, although uncommon, should be closely watched for during treatment. The initial changes may be subtle and may mimic other processes that may deceive both patient and physician. Patients should be counseled about the remote possibility of pigmentation with the understanding that any such changes should resolve upon discontinuation of the drug. The time required for resolution depends upon the degree of pigmentation and may take longer than a year in extensive cases.