History
In most cases, the condition does not lead to any subjective complaint and is observed only as an incidental finding. Pruritus is occasionally present, as is roughness of the skin. Pruritus may be more common when lesions are present on the trunk and arms of young adults. In younger patients, the chief complaint may be a cosmetic concern about facial lesions, which are frequently confused with open comedones. In this setting, patients may report a history of unsuccessful treatment for acne.
Physical Examination
Pertinent physical findings of trichostasis spinulosa are limited to the skin. Because spinous plugs may be inapparent to the naked eye, examination of suspected lesions under a hand lens or with a dermatoscope is recommended. [4]
Lesions typically appear as dark, follicular plugs or papules. The lesions may have protruding tufts or spines of fine hair that can easily be removed with a comedo extractor or small-toothed forceps without discomfort to the patient. The horny plugs are soft and contain 5-25 hairs per plug. Scales may sometimes be present. Note the image below.
Lesions may occur anywhere on the body, but they characteristically appear on the face, especially the nose, and the upper part of the trunk and arms, especially the interscapular area. Lesions less typically appear on other areas of the head, neck, and cheeks. One report describes trichostasis spinulosa on the back. [4]
Lesions are characteristically less than or equal to 1 mm.
Lesions characteristically are black.
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Small, dark, follicular papules on the nose.
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Biopsy specimen demonstrates a dilated follicle that contains numerous vellus hairs and keratin debris.
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Potassium hydroxide mount of an extracted plug reveals multiple vellus hairs embedded in keratinous material.
