Tinea Versicolor (Pityriasis versicolor) NOT a dermatophyte infection Caused by saprophytic, lipid-dependent

Disorders of Pigmentations - Hypopigmentation and Hyperpigmentation - Differential Diagnosis Algorithm HYPOPIGMENTATION Diffuse Congenital - Generalized hypopigmentation of hair, eyes, skin • Phenylketonuria • Albinism • Piebaldism Diffuse Acquired • Vitiligo Localized Congenital • Tuberous sclerosis (white "ash leaf" macules) Localized Acquired • Tinea versicolor (can also be hyperpigmented) • Pityriasis alba • Vitiligo • Post-inflammatory hypopigmentation HYPERPIGMENTATION Diffuse: • Tanning • Adverse cutaneous drug eruption • Addison's disease • Hemochromatosis • Porphyria cutanea tarda Congenital: • Café au lait macules (neurofibromatosis or McCune Albright syndrome) • Congenital melanocytic nevi Acquired: • Freckles (ephelides) • Lentigines • Melasma • Tinea versicolor (more commonly hypopigmented) • Post-Inflammatory hyperpigmentation #Hypopigmentation #Hyperpigmentation #disorders #skin #dermatology #Differential #Diagnosis #Algorithm #causes

Papulosquamous Skin Rash - Differential Diagnosis Algorithm Erythrematous or violaceous papules & plaques with overlying scale • Psoriasis - Well demarcated plaques, thick silvery scale on elbows & knees. Auspitz sign, Koebner's phenomenon • Lichen Planus - Purple, pruritic, polygonal, planar (flat-topped) papules on wrists/ankles/genitals (especially penis) Wickham's striae, Koebner's phenomenon • Pityriasis Rosea - Oval, tannish-pink or salmon-coloured patches, plaques with scaling border in Christmas tree pattern on trunk, begins with a large lesion patch Herald's atch • Tinea (Ring Worm) - Annular (Ring- shaped) lesion with elevated scaling, red border, central clearing • Secondary Syphilis - Red brown or copper coloured scaling papules and plaques on palms and soles • Discoid Lupus Erythematous - Scarring and/or atrophic red/purple plaques with white adherent scales on sun-exposed area #Papulosquamous #SkinRash #dermatology #Differential #Diagnosis #Algorithm #causes

Common Dermatological Conditions - Distribution and Morphology • Acne vulgaris - Face, upper back, chest - Open and closed comedones, erythematous papules, pustules, cysts • Rosacea - Blush area of cheeks, nose, forehead, chin - Erythema, telangiectases, papules, pustules • Seborrheic dermatitis - Scalp, eyebrows, perinasal areas - Erythema with greasy yellow-brown scale • Atopic dermatitis - Antecubital and popliteal fossae; may be widespread - Patches and plaques of erythema, scaling, and lichenification; pruritus • Stasis dermatitis - Ankles, lower legs over medial malleoli - Patches of erythema and scaling on background of hyperpigmentation associated with signs of venous insufficiency • Dyshidrotic eczema - Palms, soles, sides of fingers and toes - Deep vesicles • Allergic contact dermatitis - Anywhere - Localized erythema, vesicles, scale, and pruritus (e.g., fingers, earlobes-nickel; dorsal aspect of foot-shoe; exposed ivy) • Psoriasis - Elbows, knees, scalp, lower back, fingernails (may be generalized) - Papules and plaques covered with silvery scale; nails have pits • Lichen planus - Wrists, ankles, mouth (may be widespread) - Violaceous flat-topped papules and plaques • Keratosis pilaris - Extensor surfaces of arms and thighs, buttocks - Keratotic follicular papules with surrounding erythema • Melasma - Forehead, cheeks, temples, upper lip - Tan to brown patches • Vitiligo - Periorificial, trunk, extensor surfaces of extremities, flexor wrists, axillae - Chalk-white macules • Actinic keratosis - Sun-exposed areas - Skin-colored or red-brown macule or papule with dry, rough, adherent scale • Basal cell carcinoma - Face - Papule with pearly, telangiectatic border on sun-damaged skin • Squamous cell carcinoma - Face, especially lower lip, ears - Indurated and possibly hyperkeratotic lesions often showing ulceration and/or crusting • Seborrheic keratosis - Trunk, face - Brown plaques with adherent, greasy scale; "stuck on" appearance • Folliculitis - Any hair-bearing area - Follicular pustules • Impetigo - Anywhere - Papules, vesicles, pustules, often with honey-colored crusts • Herpes simplex - Lips, genitalia - Grouped vesicles progressing to crusted erosions • Herpes zoster - Dermatomal, usually trunk but may be anywhere - Vesicles limited to a dermatome (often painful) • Varicella - Face, trunk, relative sparing of extremities - Lesions arise in crops and quickly progress from erythematous macules, to papules, to vesicles, to pustules, to crusted sites. • Pityriasis rosea - Trunk (Christmas tree pattern); herald patch followed by multiple smaller lesions - Symmetric erythematous patches with a collarette of scale • Tinea versicolor - Chest, back, abdomen, proximal extremities - Scaly hyper- or hypopigmented macules • Candidiasis - Groin, beneath breasts, vagina, oral cavity - Erythematous macerated areas with satellite pustules; white, friable patches on mucous membranes • Dermatophytosis - Feet, groin, beard, or scalp - Varies with site, (e.g„ tinea corporis-scaly annular plaque) • Scabies - Groin, axillae, between fingers and toes, beneath breasts - Excoriated papules, burrows, pruritus • Insect bites - Anywhere - Erythematous papules with central puncta • Cherry angioma - Trunk - Red, blood-filled papules • Keloid - Anywhere (site of previous injury) - Firm tumor, pink, purple, or brown • Dermatofibroma - Anywhere - Firm red to brown nodule that shows dimpling of overlying skin with lateral compression • Acrochordons (skin tags) - Groin, axilla, neck - Fleshy papules • Urticaria - Anywhere - Wheals, sometimes with surrounding flare; pruritus • Transient acantholytic dermatosis - Trunk, especially anterior chest - Erythematous papules • Xerosis - Extensor extremities, especially legs - Dry, erythematous scaling patches; pruritis #dermatology #rash #differential #diagnosis #skin #common #distribution #primarycare

A quick infographic on various pearls about atopic dermatitis, a disease with an increasing burden on medicine and the patient. Herein, viewers can learn about possible risk factors, management recommendations, treatments, and comorbidities of atopic dermatitis. Atopic Dermatitis (AD) is a chronic, relapsing, inflammatory skin disease, affecting greater than 15% of children worldwide. This disease imposes a considerable burden on the physical, mental, and overall well-being of the patient. A combination of dysfunction of the skin barrier, cytokines, chemokines, and receptors in the skin result in the development of AD. #management #medications #treatment #diagnosis #causes #atopy #atopic #dermatitis #eczema #dermatology #skinrash References: Danby SG, Brown K, Wigley AM, et al. The Effect of Water Hardness on Surfactant Deposition after Washing and Subsequent Skin Irritation in Atopic Dermatitis Patients and Healthy Control Subjects. J Invest Dermatol. 2018;138(1):68-77. Gdalevich M, Mimouni D, David M, Mimouni M. Breast-feeding and the onset of atopic dermatitis in childhood: a systematic review and meta-analysis of prospective studies. J Am Acad Dermatol. 2001;45(4):520-527. Petersen EBM, Skov L, Thyssen JP, Jensen P. Role of the Gut Microbiota in Atopic Dermatitis: A Systematic Review. Acta Derm Venereol. 2019;99(1):5-11. Hui RL, Lide W, Chan J, Schottinger J, Yoshinaga M, Millares M. Association between exposure to topical tacrolimus or pimecrolimus and cancers. Ann Pharmacother. 2009;43(12):1956-1963. Peroni DG, Piacentini GL, Cametti E, Chinellato I, Boner AL. Correlation between serum 25-hydroxyvitamin D levels and severity of atopic dermatitis in children. Br J Dermatol. 2011;164(5):1078-1082. Taheri A, Cantrell J, Feldman SR. Tachyphylaxis to topical glucocorticoids; what is the evidence? Dermatol Online J. 2013;19(7):18954. Mehta AB, Nadkarni NJ, Patil SP, Godse KV, Gautam M, Agarwal S. Topical corticosteroids in dermatology. Indian J Dermatol Venereol Leprol. 2016;82(4):371-378. Okwundu N, Cardwell LA, Cline A, Unrue EL, Richardson IM, Feldman SR. Topical corticosteroids for treatment-resistant atopic dermatitis. Cutis. 2018;102(3):205-209. Hindley D, Galloway G, Murray J, Gardener L. A randomised study of "wet wraps" versus conventional treatment for atopic eczema. Arch Dis Child. 2006;91(2):164-168. Sandhu JK, Wu KK, Bui TL, Armstrong AW. Association between atopic dermatitis and suicidality: A systematic review and meta-analysis. JAMA Dermatol. 2019;155(2):178-187. Schmitt J, Buske-Kirschbaum A, Tesch F, et al. Increased attention-deficit/hyperactivity symptoms in atopic dermatitis are associated with history of antihistamine use. Allergy. 2018;73(3):615-626. Pedersen MS, Benros ME, Agerbo E, et al. Schizophrenia in patients with atopic disorders with particular emphasis on asthma: A Danish population-based study. Schizophr Res. 2012;138(1):58-62. Ascott A, Mulick A, Yu AM, et al. Atopic eczema and major cardiovascular outcomes: A systematic review and meta-analysis of population-based studies. J Allergy Clin Immunol. 2019;143(5):1821-1829. doi:10.1016/j.jaci.2018.11.030