Cutaneous pseudolymphomas.

Cutaneous pseudolymphoma refers to a heterogeneous group of benign reactive T- or B-cell lymphoproliferative processes of diverse causes that simulate cutaneous lymphomas clinically and/or histologically. The inflammatory infiltrate is bandlike, nodular, or diffuse and is composed predominantly of lymphocytes with or without other inflammatory cells. Depending on the predominant cell type in the infiltrate, cutaneous pseudolymphomas are divided into T- and B-cell pseudolymphomas. Cutaneous T-cell pseudolymphomas include idiopathic cutaneous T-cell pseudolymphoma, lymphomatoid drug reactions, lymphomatoid contact dermatitis, persistent nodular arthropod-bite reactions, nodular scabies, actinic reticuloid, and lymphomatoid papulosis. Cutaneous B-cell pseudolymphomas include idiopathic lymphocytoma cutis, borrelial lymphocytoma cutis, tattoo-induced lymphocytoma cutis, post-zoster scar lymphocytoma cutis, and some persistent nodular arthropod-bite reactions. This review attempts to discuss current aspects of the classification, pathogenesis, clinical spectrum, histopathologic and immunohistochemical diagnosis, and laboratory investigations for clonality in the various types of cutaneous pseudolymphomas.

Cutaneous Crohn's disease in children.

BACKGROUND: Although cutaneous Crohn's disease is well recognized in adults, in children it is extremely rare. OBJECTIVE: Our purpose was to describe five children with cutaneous Crohn's disease and to review the literature. METHODS: The medical records of five children with cutaneous Crohn's disease were retrospectively reviewed for clinical features and laboratory data. An extensive review of the literature was conducted. RESULTS: Five children, one boy and four girls, 6 to 12 years of age at onset, had cutaneous manifestations of Crohn's disease. Three had genital swelling, and the other 2 had buttock abscesses. Most were seen before the diagnosis of gastrointestinal Crohn's disease was made. There have been 80 cases of cutaneous Crohn's disease described, including our series. Only 14 were in children. Two thirds of children with cutaneous Crohn's disease had genital involvement compared with about half of the adult cases. Sixteen of the 80 patients had cutaneous lesions without preceding gastrointestinal Crohn's disease. Of these, approximately 70% had genital lesions. CONCLUSION: Although Crohn's disease is common in children, cutaneous manifestations are rarely a presenting sign. However, when cutaneous Crohn's disease is present in children, it commonly precedes the gastrointestinal disease.

Childhood white superficial onychomycosis caused by Trichophyton rubrum: report of seven cases and review of the literature.

BACKGROUND: Although white superficial onychomycosis (WSO) is well recognized in adults and considered to be mainly caused by Trichophyton mentagrophytes, childhood WSO is rare. WSO caused by Trichophyton rubrum in prepubertal children has never been reported. OBJECTIVE: Our purpose was to describe the existence of WSO in children and to emphasize that T. rubrum may be its main cause. METHODS: Seven children with WSO seen between 1988 and 1993 were examined. Only patients who had a positive potassium hydroxide preparation and a positive fungal culture were included. RESULTS: Seven healthy prepubertal children, 2 to 9 years of age, were identified with WSO. All cases were proved to be caused by T. rubrum. Six patients had associated tinea pedis, and five had a family history of tinea pedis. Topical antifungal therapy was partially effective in some cases. CONCLUSION: This report documents the existence of WSO in prepubertal children. All cultures grew T. rubrum. Although onychomycosis is not as common in prepubertal children as in adults, it may be underrecognized.

Follicular psoriasis: an under-reported entity. A report of five cases.

Follicular psoriasis is not rare in dermatological practice, although only a few cases have been reported. We describe five patients with follicular psoriasis, one man and four women. The patients ranged in age from 23 to 73 years. Lesions consisted of erythematous scaly follicular papules located on the trunk and extremities. Two patients had associated plaque-type psoriasis of the scalp. None had nail involvement at the time of diagnosis. Histological examination of several biopsy specimens revealed the changes of psoriasis in the follicular epithelium.

Chronic meningococcemia in childhood: case report and review of the literature.

Chronic meningococcemia is a rare form of meningococcal infection. Most reported cases occur in adults. Only about 10% of reported patients are under 18 years of age. We herein report chronic meningococcemia in a 17-month-old immunocompetent child and review the literature. Our patient had a 4-month history of several episodes of intermittent fever accompanied by widespread erythematous and purpuric, crusted papules and pustules with necrotic centers. Blood cultures were positive for group C Neisseria meningitidis. Histopathology of a skin biopsy specimen revealed leukocytoclastic vasculitis. Because the disease is uncommon and can be confused with other conditions including other infectious processes, vasculitis, and collagen vascular diseases, it is important to have a high degree of suspicion for chronic meningococcemia. This will help avoid a delayed diagnosis and/or inappropriate treatment. The positive blood culture remains the diagnostic sine qua non. Treatment with ceftriaxone was rapidly successful in our patient.

Treatment of idiopathic guttate hypomelanosis with liquid nitrogen: light and electron microscopic studies.

Idiopathic guttate hypomelanosis is a common skin disorder of unknown cause. Our studies have shown that significantly fewer dopa-positive melanocytes are in the white macules of idiopathic guttate hypomelanosis than in normal skin. By electron microscopy we observed that the melanocytes in the lesional skin were round and less dendritic with fewer melanosomes than in normal pigment cells. Lesions gently frozen with liquid nitrogen repigmented in 6 to 8 weeks. The number of dopa-positive melanocytes was significantly greater in the repigmented areas than in untreated lesions but less than in normal skin.