These are firm, fibrous papules, often part of tuberous sclerosis, lacking the comedones or pustules seen in inflammatory acne or rosacea.
Distinguished by a clear history of exposure to specific industrial oils or chemicals and a monomorphic appearance, which is absent in other forms.
Presents as rapidly growing, firm nodules or tumors, not as the comedones and pustules characteristic of acne vulgaris.
This is a single, giant solitary comedone, easily distinguished from the multiple, smaller lesions of typical acne.
Identified by its familial inheritance pattern and widespread comedones on the trunk and extremities, beyond typical acne distribution.
Presents as large open comedones and cysts specifically on sun-damaged skin around the eyes in older individuals, a different demographic and location than typical acne.
These are multiple, dome-shaped, skin-colored papules, often associated with Birt-Hogg-Dubé syndrome, and lack the inflammatory component of acne.
Characterized by boggy, infiltrated plaques with associated hair loss, a presentation entirely different from the papules and pustules of acne.
Presents as monomorphic (all same stage) pustules centered on hair follicles, often itchy, and notably lacks the comedones that are the hallmark of acne vulgaris.
Distinguished by its onset within the first few months of life due to maternal hormones, resolving spontaneously, unlike the adolescent onset of acne vulgaris.
Characterized by monomorphic, reddish-brown papules on the central face that heal with scarring, but crucially lacks comedones.
These are tiny, firm, white keratin cysts that are not centered on a follicle and cannot be expressed like the open or closed comedones of acne.
This is a congenital or early-onset hamartoma presenting as a linear or grouped arrangement of comedones, a localized pattern distinct from the diffuse nature of acne.
Directly linked to a history of occlusive products (like heavy pomades on the forehead) or gear, which is not a factor in a typical acne.
These are multiple, hard, bone-like papules within the skin, which can be confirmed by their stony feel, unlike the softer lesions of acne.
Characterized by clusters of small papules and pustules specifically around the mouth while sparing a thin border around the lips, a classic distribution not seen in acne.
Caused by shaved hairs growing back into the skin, this is confined to the beard area and lacks the true comedones seen in acne.
The key differentiator is the complete absence of comedones, coupled with flushing and persistent redness (erythema) in a central facial distribution.
Presents as reddish-brown papules or nodules ("apple-jelly" on diascopy) and is confirmed by a biopsy showing non-caseating granulomas, unlike the follicular inflammation of acne.
These are yellowish, umbilicated papules seen in older adults, representing enlarged oil glands, and are distinct from the inflammatory lesions of acne.
Identified by its monomorphic eruption of papules and pustules (all in the same stage) and a clear history of steroid use, along with the absence of comedones.
These are benign sweat duct tumors appearing as small, skin-colored, flat-topped papules, most commonly under the eyes, a location and morphology distinct from acne.
These are small, pale, disc-shaped papules, often associated with Birt-Hogg-Dubé syndrome, and are non-inflammatory.
These are benign, skin-colored tumors typically on the central face that lack the inflammatory or comedonal features of acne.
Presents as dark, bristle-like plugs within follicles, representing retained vellus hairs, which can be pulled out, unlike the keratin plugs of acne comedones.
