<unk>  lesions are so called because of their "lichen-like" appearance and can be classified by the site they involve, or by their morphology. Site<unk>  may be categorized as affecting mucosal or cutaneous surfaces. * Cutaneous forms are those affecting the skin, scalp, and nails. * Mucosal forms are those affecting the lining of the gastrointestinal tract (mouth, pharynx, esophagus, stomach, anus), larynx, and other mucosal surfaces including the genitals, peritoneum, ears, nose, bladder and conjunctiva of the eyes. Pattern<unk>  lesions can occur in many different forms: Lesion morphology Description Papular Papular form is the classic cutaneous<unk>  (CLP) lesion characterized by shiny, red or purple-colored, flat-topped papule. Lesions may have a thin, transparent, and adherent scale. Fine whitish points or lacy lines (Wickham's striae) may be seen on the surface of well-developed papules. Annular 'Ring-shaped' lesions that develop gradually from single small pigmented spots into circular groups of papules with clear, unaffected skin in the center. The ring-like lesions may very slowly enlarge, co-join and morph into larger irregular (serpentine) bands, sometimes accompanied by lines (See Linear, below). Annular CLP is uncommon and classically involves the male genitalia (glans penis and penile shaft), groin, axilla and also the extremities. Linear Papules are arranged in a line (the "Blaschko line"). This pattern may develop secondary to trauma (koebnerization) or, uncommonly, as a spontaneous, isolated eruption, usually on the extremities, and rarely on the face. Hypertrophic This pattern is characterized by hyperkeratotic thick pruritic red-brown to purple-gray plaques with follicular accentuation. Hypertrophic CLP commonly involves the extremities, especially the interphalangeal joints and the anterior legs in a symmetrical distribution. This form is also known as<unk>  verrucosus". Atrophic This morphology is characterized by the presence of a few well-demarcated, white-bluish papules or plaques with central superficial atrophy. Atrophic CLP is the clinical endpoint of chronic annular or hypertrophic<unk>  with atrophic lesions. The use of potent topical corticosteroids for a long-term may predispose the patient to developing atrophic lesions. Bullous This morphology is characterized by the development of vesicles and bullae with the skin lesions. This is a rare variant of<unk> , and also known as "vesiculobullous<unk> ." Actinic Rare form presenting as nummular patches or plaques with a hypopigmented halo surrounding a hyperpigmented center. Actinic CLP is more prevalent in African Americans, Indians, and Middle-Eastern individuals and commonly affects the sun-exposed areas. Ulcerative This morphology is characterized by chronic, painful bullae and ulceration of the feet, often with cicatricial sequelae evident. This is a rare variant of<unk> . Pigmented This morphology is characterized by hyperpigmented, dark-brown macules in sun-exposed areas and flexural folds. This is a rare variant of<unk> . Follicular Characterized by follicular, flat, elevated or hemispherical erythematous papules with or without keratoses presenting in groups or disseminated. The Graham‐Little‐Piccardi‐Lasseur syndrome, seen in a familial pattern and also predominantly in women, is characterized by the appearance of follicular<unk>  on the trunk with<unk>  follicularis decalvans on the scalp. Follicular<unk>  on the scalp is more likely to lead to scarring alopecia. Inverse Characterized by extensive erythematous lesions with poorly defined borders and in part with lichenification. Inverse<unk>  typically affects the axillae, inguinal creases, limb flexures and submammary region. Pigmentation of the individual lesions at these inverse locations are typical. Additionally, keratotic papules and erosions with a bizarre configuration can occur. Overlap syndromes Occasionally,<unk>  is known to occur with other conditions. For example: * Lupus erythematosus overlap syndrome. Lesions of this syndrome share features of both lupus erythematosus and<unk> . Lesions are usually large and hypopigmented, atrophic, and with a red to blue colour and minimal scaling. Telangectasia may be present. * Lichen sclerosus overlap syndrome, sharing features of<unk>  and lichen sclerosus.
Lichen planus
Geographic tongue
Lichen nitidus
Leukoplakia
Lichen simplex chronicus
Lichen myxedematosus
Lichen sclerosus
Tinea barbae