Distinguishing hypertrophic scar (HS) from keloid histopathologically is sometimes difficult because thickened hyalinized collagen (keloidal collagen), the hallmark of keloid, is not always detectable and alpha-smooth muscle actin (alpha-SMA), a differentiating marker of HS, is variably expressed in both forms of scar. The aim of this study was to investigate additional distinguishing features to facilitate differentiation between keloid and HS. We compared various histologic features and the expression of alpha-SMA in 40 specimens of keloid and 10 specimens of HS. The features more commonly seen in keloids were: (a) no flattening of the overlying epidermis, (b) no scarring of the papillary dermis, (c) presence of keloidal collagen, (d) absence of prominent vertically oriented blood vessels, (e) presence of prominent disarray of fibrous fascicles/nodules, (f) presence of a tongue-like advancing edge underneath normal-appearing epidermis and papillary dermis, (g) horizontal cellular fibrous band in the upper reticular dermis, and (h) prominent fascia-like fibrous band. The last three features were found in keloid specimens only, including the ones lacking detectable keloidal collagen. Our study confirmed the diagnostic value of keloidal collagen, but it was only found in 55% of keloid specimens. Alpha-SMA expression was found in both HS (70%) and keloid (45%), thus it would not be a differentiating marker. In scars with no detectable keloidal collagen, the presence of the following feature(s) favors the diagnosis of keloid: non-flattened epidermis, non-fibrotic papillary dermis, a tongue-like advancing edge, horizontal cellular fibrous band in the upper reticular dermis, and prominent fascia-like band.

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Fox-Fordyce disease (FFD) is a rare skin disease manifesting as multiple pruritic follicular papules involving the skin-bearing apocrine glands. Reports of FFD in Asian people are scant. In this retrospective study, we describe the clinicopathological findings of five cases of FFD affecting Taiwanese subjects. Clinically, all patients presented with numerous uniform, 2-3-mm, skin-colored to light brown, dome-shaped papules with smooth surface, which were distributed in the apocrine gland-containing areas. Pruritus varied from mild to severe. The histopathology is characterized by focal spongiosis in the upper infundibulum with perifollicular fibrosis and lymphohistiocytic infiltrate. FFD needs to be differentiated from lichen amyloidosis, Darier's disease, syringoma, lichen simplex chronicus and spongiotic dermatitis clinically or pathologically. The findings of focal spongiosis in upper infundibulum associated with a perifollicular lymphohistiocytic infiltrate can facilitate the diagnosis of FFD.

We report the clinicomycologic study of 27 culture‐proven cases of tinea capitis from southern Taiwan during the years 1988 to 1990. The series is notable for its predominance of adults (63%), of women (89%), and of Trichophyton violaceum infection (74%). The age distribution was clearly bimodal; the median age was 6 years for children and 56 years for adults (older than 18 years). Whether or not these findings represent a new trend of tinea capitis in southern Taiwan remains to be determined. Clinically, our cases of black‐dot ringworm caused by T. violaceum often presented with subtle changes of scaling, hair loss, and black dots. The keys to the correct diagnosis are (1) a high clinical index of suspicion with careful inspection of the scalp for the presence of black dots, and (2) microscopic examination and culturing of the black dots or plucked hairs.

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