Rickettsia honei Infection in a Traveler Returning From India.

We report a case of Rickettsia honei infection in a US tourist returning from India and the Himalayas. This case highlights a need for awareness of various Rickettsia species endemic to India and the importance for physicians to consider rickettsial diseases in returning travelers with eschar or rash-associated febrile illnesses.

Keloid formation occurring in the distribution of a congenital vascular malformation.

A 35-year-old African American man presented with complaints of malodorous drainage from hypertrophic lesions on his occipital scalp (Figure 1, inset). The patient had no family history of keloid formation and no other keloids on his body. The hypertrophic mass on his scalp had been present for 10 years and had not been a result of any type of mechanical, surgical, or laser treatment. It corresponded to the distribution of a large vascular malformation over the occiput (Figure 1). The vascular malformation extended from the occipital scalp to the right parietal scalp, the right side of the face, neck, upper chest, and right arm, with varicosities and hypertrophy of the right upper extremity (Figure 2). The vascular malformation over the right parietal scalp and ear was characterized by bleb formation and hypertrophy of the right ear. The patient reported that no manipulation, including laser treatment, of the vascular malformation had been previously performed. He did state that a previous dermatologist had attempted serial surgical excision of the cerebriform nodules but retired during the course of treatment. He stated that the appearance of his keloid formation and port-wine stain had not changed during the past 10 years. A previous biopsy of a hypertrophic lesion showed histologic findings consistent with folliculitis keloidalis nuchae. Cephalexin 500 mg 4 times daily for 14 days was prescribed for the purulent drainage. A Doppler ultrasound was ordered of the right upper extremity to evaluate for an arteriovenous malformation and showed no evidence of venous thrombosis or arteriovenous malformation. On a second visit 2 weeks later, the hypertrophic lesions continued to show drainage. Clindamycin gel to be applied twice daily to the scalp was added. The patient also had magnetic resonance imaging with and without gadolinium contrast (Figure 3) ordered, which showed a large hypertrophic giant scalp keloid overlying the occipital and suboccipital region measuring 12x 19 cm. There was soft tissue thickening involving the right external ear, extending inferior to the right ear, overlying an intact parotid gland. There was no evidence of muscular or skull invasion.

Severe insulin resistance associated with subcutaneous amyloid deposition.

A 59-year-old man with type 1 diabetes mellitus presented with severe resistance to subcutaneously injected insulin. Histological analysis of the injection sites, demonstrated foreign body type granulomas surrounding areas of amyloidosis. It is suggested that the granulomas were the source of an insulin-degrading enzyme (IDE) which simultaneously degraded amyloidogenic precursors into localized amyloid deposits. These findings may add insight into the role of insulin-degrading enzymes in the etiology of subcutaneous insulin resistance syndromes.

Dyshidrotic-like spongiotic dermatitis after intravenous immunoglobulin therapy.

Intravenous immunoglobulin (IVIG) therapy has been used to treat a variety of immune mediated disorders. Cutaneous reactions to IVIG are rare and have only been anecdotally described. We describe three cases with dyshidrotic-like biopsy proven spongiotic dermatitis after administration of IVIG. These three cases may highlight an uncommon and rarely reported side effect of IVIG.

A patient with extensive stem cell factor-induced hyperpigmentation.

Stem cell factor (SCF) is a cytokine that stimulates development of erythroid precursors and, consequently, may have potential importance in the treatment of certain anemias. We report a case of a young woman with Diamond-Blackfan anemia who received SCF treatment. One effect of SCF treatment is cutaneous hyperpigmentation at the injection site. In contrast to previously reported cases of patients who had fewer SCF injections, her hyperpigmentation was extensive and of major cosmetic concern. SCF may play a role in a number of disease processes. This case demonstrates the need to consider the potential pigmentary side effects of SCF therapy and to make careful selection of the injection sites.

Cutaneous Rosai-Dorfman disease: comprehensive review of cases reported in the medical literature since 1990 and presentation of an illustrative case.

BACKGROUND: The latest comprehensive review of primary cutaneous Rosai-Dorfman disease was published as part of an exhaustive survey of sinus histiocytosis with massive lymphadenopathy in 1990. Since then, much progress has been made in the understanding of malignant lymphoma and benign disorders of lymphoid and histiocytic origin. OBJECTIVE: We reviewed cases of primary cutaneous Rosai-Dorfman disease published since 1990 and discuss their clinical and pathologic features, comparing them with cases of systemic Rosai-Dorfman disease. METHODS: We conducted a search of the National Library of Medicine PubMed database for cases of cutaneous Rosai-Dorfman disease reported in the English-language medical literature since February 1990. RESULTS: We identified 72 patients with cutaneous Rosai-Dorfman (female to male ratio 1:0.5). The gross appearance and number or distribution of lesions were highly variable. Abnormal laboratory data included peripheral blood cytopenias (10 patients) and increased gammaglobulin fraction (10 patients). The response to treatment was variable. CONCLUSION: Purely cutaneous disease without the characteristic lymphadenopathy is rare but has been increasingly reported in the literature. Compared with patients with systemic Rosai-Dorfman disease, patients with primary cutaneous Rosai-Dorfman disease are older, women are more commonly affected, and whites are more likely than blacks to be afflicted.

Histiocytic sarcoma with secondary involvement of the skin and expression of CD1a: evidence of indeterminate cell differentiation?

BACKGROUND: Histiocytic sarcoma is an exceedingly rare malignant neoplasm composed of cells with a monocyte/macrophage phenotype. In the current nosology of histiocytic neoplasms, histiocytic sarcoma is separate from indeterminate cell histiocytosis, a generally benign disorder characterized by proliferation of a CD1a+ and S-100+ population of cells lacking Birbeck granules usually limited to the skin. METHODS: We present a case of histiocytic sarcoma in a 64-year-old man presenting as a peritonsillar mass and secondarily involving the skin. RESULTS: The malignant cells in the extracutaneous foci of disease expressed macrophage-associated antigens including S-100 but were CD1a-. The malignant cells in the skin coexpressed CD1a and S-100 but lacked ultrastructural features of Langerhans cells, findings indicative of indeterminate cells. CONCLUSIONS: We discuss the clinical and histopathologic differential diagnosis in association with prior reported cases of histiocytic sarcoma, particularly in cases involving the skin and cases expressing the Langerhans cell-associated antigen CD1a.