Derm terms Flashcards
Macula - primary lesion
flat, circumscribed, <1cm
Patch - primary
Flat, circumscribed, >1 cm
Papule - primary
Elevated, circumscribed, <1 cm
Pseudofolliculitis
- Consists of papules, but not pustules.
- Is often seen in the beard area.
- Can be distinguished from acne because the inflammation is adjacent to hair follicles.
- The hair grows out of the follicle and, when shaved closely, often grows back in to the surrounding skin, causing irritation and inflammation
Plaque- primary
Elevated, broad (or confluence of papules); > 1 cm
Vesicles - primary
Fluid filled, circumscribed, < 1 cm
Bullae- primary
Fluid filled, circumscribed, > 1 cm
Pustule- primary
Exudate filled, circumscribed
Nodule- primary
Elevated dermis +/- subQ, circumscribed (majority underskin)
Urticaria- primary
“wheals” Blanching edematous, thin erythematous papule/plaque +/- hypopigmented rim. Maybe white-pale red often disappear after a couple hrs
Telangiectasia- primary
Dilated superficial bv/caps, visible on skin
Petechiae- primary
Tiny red/purple macules via cap hemorrhage, no blanching
Purpura- primary
Lg purple macules/papule via bleeding under skin, no blanching
Scale- 2ndary
flakes of keratin coarse/fine, loose/adherent
Crust- 2ndary
dried serum/ blood/ pus on top of skin
Fissure- 2ndary
linear cleavage on skin
Depression through dermis/sub q +/- scar
Depression through epidermis, no scar
Excoriation - superficial skin loss, often linear, via scratching/rubbing
Infant rashes x 4
- Seborrheic dermatitis (cradle cap)
- Eczema or Atopic Dermititis
- Candidal rash
- Psoriasis
Seborrheic dermatitis
- Consists of erythematous plaques with fine to thick, greasy yellow scale.
- Typically seen on the scalp, but may spread to the ears, neck, and diaper area of infants.
Treatment
For infants, treatment can include:
- Baby oil and a small brush to remove the scales
- Frequent (i.e., daily) shampoong with a gentle baby shampoo, or-for more persistent cases-use of a prescription shampoo containing ketoconazole, an anti-fungal agent, or pyrithione zinc. Care must be taken not to get the shampoo in the infant’s eyes.
In older patients it is often caused by a fungus (Malassezia).
- A low-potency topical steroid cream (e.g., hydrocortisone). In older children and adults, ketoconazole cream may be used.
Eczema or atopic dermatitis
- May involve the posterior scalp.
- A positive history of atopic diathesis would support this diagnosis.
- Look for pruritic, erythematous, scaling plaques on extensor surfaces as evidence of atopic dermatitis on other areas of the body.
Candidal rash
- Commonly manifests as a diaper dermatitis peaking between 7-10 months of age.
- Characterized by an area of erythema in the inguinal region, as well as erythematous papules and plaques with satellite lesions.
Psoriasis
- More erythematous, with a thicker, non-waxy scale and more defined borders than seborrheic dermatitis.
- May or may not be pruritic.
- A family history of psoriasis is present in 40% of patients.
Open comedones (black heads) Acne
Closed comedones (white heads) Acne
Differential Diagnosis for Pustular Conditions
- Staphylococcal folliculitis, Furunculosis
- Acne vulgaris
- Hidradenitis suppurativa
- Rosacea
- Perioral dermatitis
Acne Vulgaris
Due to several processes:
- Keratinous material and excess sebum (due to androgenic influence) plug the pilosebaceous gland.
- Increased sebum provides a growth medium for superinfection with Propioniobacterium acnes.
Areas of the body with the greatest number of sebaceous glands usually affected, including:
- Neck
- Face
- Chest
- Upper back
- Upper arms
Staph folliculitis
- Can be very similar to nodular or cystic acne.
- Often below waist or in groin area.
Hidradenitis suppurativa
- Pustular lesions caused by occlusion of the apocrine follicular units (instead of the pilosebaceous units).
- Often superinfected with Staphylococcus aureus or Streptococcus pyogenes.
Distribution markedly different from acne.
- Areas most likely affected in women: Axillae, Groin, Inframammary regions
- In men:
- Perineal and perianal areas more commonly affected.
Rosacea
- More often seen in adults.
- “Early” form seen in adolescents is characterized by inflammatory papules and micropustules, and redness.
- No comedones.
- Worsens with alcohol, spicy food, temperature extremes, and stress.
- Can be treated with topical metronidazole and various other medications.
- Distribution - malar & nasal surfaces
Periorbital dermatitis
- A variant of rosacea also commonly seen in adolescents, and treated the same way.
- See erythema, scaling, and papules or pustules, but no comedones.
- Distribution = “Perioral” almost a misnomer, as this may be seen around the mouth, nose, or eyes.
Erythema nodosum
- Hypersensitivity reaction presenting as red, tender, nodular lesions on pretibial surface of the legs.
- Many possible etiologies, a few of which include infections, drugs, and inflammatory bowel disease.
- Primary lesions are nodules, not pustules.
