Accessory Tragus

Accessory tragus or have Synonyms Supernumerary ear, supernumerary auricle, accessory external ear, rudimentary auricle, accessory auricle, auricular appendage

cervical auricle, preauricular appendage, cutaneous cervical tag, preauricular appendage, Wattle.

This dermatology disease is Congenital anomaly of branchial arch development, producing a preauricular papule.

The Pathogenesis Abnormal development of portions of one of the branchial arches

The Clinical manifestation are such as  Asymptomatic, solitary, flesh-colored papule, usually in the preauricular area; vellus hairs arise from the papule

The Differential diagnosis fro this dermatoly disease are  Preauricular cyst or sinus; thyroglossal duct cyst; branchial cyst or sinus; bronchogenic cyst; acrochordon; melanocytic nevus; epidermoid cyst; neurofibroma

Therapy that usually do for this disease is only Surgical excision .

For more information about this dermatology disease , you can read a book by  Jansen T; Romiti R; Altmeyer P (2000) Accessory tragus: report of two cases and review of the literature. Pediatric Dermatology 17:391–394

Acanthosis Nigricans

Acanthosis nigricans is caused by Hyperpigmented, velvety thickening of the skin; most commonly on the neck, in the axillae, and in the groin

The pathogenesis Caused by factors that stimulate epidermal keratinocyte and dermal fibroblast proliferation, such as insulin or an insulin-like growth factor

The Clinical manifestation is Symmetrical, hyperpigmented, velvety plaques, which most commonly appear in the intertriginous areas; skin tags in the

vicinity of the plaques

The differential diagnosis that you can see are Becker nevus; confluent and reticulated papillomatosis of Gougerot and Carteaud; Dowling-Degos disease; seborrheic keratosis; ichthyosis hystrix; linear epidermal nevus; parapsoriasis en plaque; pemphigus vegetans; hemochromatosis; Addison’s disease; pellagra

Therapies for this dermatology disease are correction of underlying disease process; weight reduction in obese patients; tretinoin 0.025% cream; adapalene 0.1% gel; calcipotriene; dietary fish oils; dermabrasion

For more information about this disease, you can read  Hud JA Jr, Cohen JB, Wagner JM, Cruz PD Jr (1992) Prevalence and significance of acanthosis nigricans in an adult obese population. Arch Dermatol 128: 941–944.

Acanthoma Fissuratum

Acanthoma fissuratum or have other names such as Granuloma fissuratum, spectacle frame granuloma, acanthoma fissuratum cutis . This dermatology problems is caused by  Keratotic papule or nodule which develops at the site of chronic irritation, such as under eye glasses or in the oral cavity. 

The pathogenesis is Chronic contact irritation; includes other factors such as local anatomic changes, seborrheic dermatitis, and hyperhidrosis

Clinical manifestation Oral cavity: solitary smooth-surfaced papule at the juncture of the lip and gum Face or post-auricular fold: pink papule with a longitudinal central fissure

Differential diagnosis is Oral cavity: squamous cell carcinoma. Skin: basal cell carcinoma; foreign body granuloma; chondrodermatitis nodularis helicis

Therapies  for this dermatology problem are  Removal of stimulus by changing eye glasses, dentures, etc.; surgical excision in recalcitrant cases.

If you want to know more about this dermatology problem, you can read book  Frey T, Bartak P (1992) Acanthoma supratrochantericum. Cutis 49(6): page 412–416.