*Hospital Universitario Fundación Jiménez Díaz, Ubicación Madrid, Spain; and†Department of Dermatology, Medical University Graz, Austria.
Checking for direct PDF access through Ovid
(Continued from page e158)ANSWERDisseminate and recurrent infundibulofolliculitis (DRIF) of Hitch and Lund.ADDITIONAL FINDINGSThe patient was lost in follow-up.DISCUSSIONIn 1968, Hitch and Lund described an eruption consisting of “firm follicular irregularly-shaped papules, frequently pierced by a hair resembling cutis anserine” on the torso, neck, and proximal extremities, in a (Fig. 1) young black man.1 No history of atopy was reported. Histopathologically, the disorder is characterized by a lymphocytic infiltrate within the follicular infundibulum and infundibular spongiosis. Occasional neutrophils, slight proliferation of fibroblasts, and melanophages may be observed. Variable hyperkeratosis in the upper part of the ostium is described. Regarding the broad distribution of the lesions, the recurrent course, and the involvement of the infundibula, the authors named this entity DRIF.1,2 Generally, disseminate distribution is observed; however, lesions can be isolated to the neck as well.3 Some authors propose the name of “disseminate and persistent infundibulofolliculitis” to emphasize the persistency of lesions in some patients.4 The disorder is present mainly in young black men. It has been rarely described in women3 and other races.5The validity of DRIF as a separate entity has been questioned, considering it as a variant of atopic dermatitis.6 Because it has such a distinctive clinicopathological picture and is usually unresponsive to topical steroids, it has been finally accepted as an entity.7The main histopathological differential diagnoses include keratosis pilaris, atopic dermatitis (follicular eczema), lichen nitidus (including the spinous follicular variant), lichen spinulosus, Fox–Fordyce disease (also known as apocrine miliaria), lichen planopilaris and eosinophilic folliculitis. Clinically, DRIF may resemble juxtaclavicular beaded lines that consists of papules arranged along skin tension lines in the supra- and subclavicular region; however, the histopathologic picture is different, showing hyperplastic sebaceous glands.8Atopic dermatitis presents clinically with erythematous scaly papules and plaques with varying location depending on the age of the patient; a variant with follicular lesions (follicular eczema) is described and shows histopathologically spongiosis of the follicular infundibulum and lymphocytic exocytosis that may be associated with acanthosis and focal parakeratosis of the adjacent epidermis.9 On clinical grounds, however, it may be distinguished from DRIF. Unlike follicular eczema, DRIF does not show any seasonal influence nor is there any association with atopy. In addition, follicular eczema usually responds well to topical steroid therapy, whereas DRIF is commonly unresponsive to therapy. Keratosis pilaris is a common condition, usually associated with atopic dermatitis. It is characterized by a keratin plug within hair follicles and a sparse lymphocytic infiltrate within the dermis adjacent to the follicular infundibulum. The histopathological picture is similar to DRIF and some authors consider it the same entity. However, keratosis pilaris has other predilections sites, shows no or only little follicular spongiosis and less inflammation. A keratin plug is not always found in DRIF. Lichen spinulosus is present usually in patients with atopic dermatitis. Hyperkeratotic follicular papules with a central horny spine are grouped into patches on the neck, buttocks, abdomen, and upper limbs; the disorder may be generalized.10 Histopathologically, lichen spinulosus shows follicular plugging of the infundibulum and a perifollicular infiltrate.9Lichen nitidus is characterized clinically by the presence of multiple, small flesh-colored papules, 1–2 mm in diameter with predilection for the upper extremities, chest, abdomen, and genitalia of children and young adult males. Occasionally, generalized cases are seen.11 Microscopic examination shows a dense, well-circumscribed, subepidermal lymphohistiocytic infiltrate, sharply limited to 1 or 2 adjacent dermal papillae.