2023 Reviewer Flashcards
Thickest part of the epidermis
palms and soles
Origin of keratinocytes
Ectoderm
Slow adapting touch receptors
Merkel cell
Melanocyte-keratinocyte ratio in the basal cell layer
1:4
Major component of anchoring fibrils
Collagen VII
Active growth phase of the hair follicle lasts
Anagen phase (3-5 years)
Months is needed to replace a great toe nail
12-18 months
Sebaceous glands located at the female areola
Montgomery’s tubercles
Cell is involved in Telangiectasia Macularis Eruptiva Perstans
Mast cell
Cell is involved in Telangiectasia Macularis Eruptiva Perstans
Mast cell
Cell is involved in Telangiectasia Macularis Eruptiva Perstans
Mast cell
Specialized aggregates of smooth muscle cells found between arterioles and venules
Glomus bodies
Apocrine gland in the eyelid
Glands of Moll
Growth rate of fingernails
0.1mm/day (4-6 months)
Principal component of the dermis
Collagen
Lesions arranged along the lines of cleavage (Langer lines)
Pityriasis rosea
Wavelength of Wood’s light
365nm
Breakfast-lunch and dinner sign
Anthropod bite (bed bugs, Cimex lectularius) usually follow a linear or clustered pathway in a group of 3 to 5 blood meals
Dermal hyperpigmentation (blue-black or gray-blue pigmentation). Most commonly affects the skin and sometimes the cartilage of ears and sclera of eyes caused by genetic defect in homogentisic acid oxidase (Endogenous) or hydroquinone (Exogenous).
Ochronosis
Condition with characteristic fine salmon or pink colored, scaly rash most often affecting children and young adults. (salmon pink disease)
Pityriasis Rosea
A rare inflammatory papulosquamous disorder characterize by distinct, well-demarcated plaques of various sizes with characteristic reddish-orange hue, may have varying degrees of the scale with intervening areas of unaffected skin, known as “islands of sparing”. Peculiar orange or salmon-yellow color of the follicular papules, containing a horny center. It presents as a chronic condition with small follicular papules, disseminated yellowish pink scaly patches and solid conflueny palmoplantar hyperkeratosis
Pityriasis rubra pilaris
Pityriasis rubra pilaris (PRP) is a chronic skin disease characterized by small follicular papules that coalesce into salmon colored pink scaling patches, and often, solid confluent yellow-orange palmoplantar hyperkeratosis. The papules are the most important diagnostic feature, being more or less acuminate (pointy), salmon colored to reddish brown, about pinhead sized, and topped by a central horny plug.
vitamin A deficiency - Phrynoderma (follicular hyperkeratosis)
The management of PRP is generally with systemic retinoids.
Miliaria is characterized by deep seated, whitsh papules that are asymptomatc
Miliaria Profunda
Localized erythema and swollen patches and blisters on hands and feet which appears several hours after exposure to cold air
Chilblains
Spectrum of UVA, UVB, UVC
95% uvAging (Aging, photoaging, oxidative stress, wrinkling. Absorbed by Dermis)
UVA 1 (340 - 400nm)
UVA 2 (320 - 340nm)
5% uvBurns (Burns, Erythema, Cancer. Absorbed by Epidermis)
UVB (280 -320nm)
Most prevalent during 10AM-4PM
uvCan’t pass ozone
UVC (200 - 380nm)
Cause of solar erythema
UVB
Skin phototype of a person with minimal burning and tans well
IV
Characteristic changes brought about by chronic sun exposure. Atrophy of epidermis and dermis, allowing the skin to tear and lacerate easily.
Dermatoheliosis
5 skin involvement:
Epidermis (actinic keratosis)
Dermis (solar elastosis)
Blood vessels (telangiectasia)
Sebaceous glands (solar comedones)
Melanocytes (diffuse or mottled brown patches)
Nodular elastoidosis with epidermal cysts and comedones (open/black heads, closed/white heads) on the temples, inferior periorbital and malar skin brought about by sun aging.
Favre-Racouchot syndrome
Treated with oral Isotretinoi (0.05-0.1 mg/kg/day)
Cause of phytophotodermatitis in plants
Furocoumarins or Psoralens (Apiaceae or Umbelliferae family) includes weeds, edible plants such as carrots, parsnip. Dill, fennel, celery and anise. Lesions will appear within 8-24 hours of exposure to the sap of a psoralen-containing plant followed by sun exposure
Causes berloque dermatitis (small areas of redness or pigmentation of the skin, usually on sun-exposed areas, such as the neck)
fragrance products containing bergamot oil or a psoralen are applied to the skin, followed by exposure to sunlight
Most common form of photosensitivity
Polymorphous light eruption (The most common photosensitivity is to UVA. Mainly, exposure to visible light triggers porphyria)
Pressure ulcers grading
Stage 1: just erythema of the skin.
Stage 2: erythema with the loss of partial thickness of the skin including epidermis and part of the superficial dermis.
Stage 3: full thickness ulcer that might involve the subcutaneous fat. Stage 4: full thickness ulcer with the involvement of the muscle or bones
Most common site of pressure ulcers representing 65%
Pelvic area
The bony prominences of the body are the most frequently affected sites. About 95% of all pressure ulcers develop on the lower body, with 65% in the pelvic area and 30% on the legs. The ulcer usually begins with erythema at the pressure point; in a short time a “punched-out” ulcer develops.
Non-penetrating circumscribed hyperkeratosis produced by pressure, most frequently on the palms and soles
Callus
Typical clinical picture of tense, woody fibrosis, irregular punched-out ulcerations, and a rim of hyperpigmentation at injection sites
Pentazocine
Narcotic Dermopathy
1. Heroin (diacetylmorphine)
IV injection - thrombosed, cordlike, thickened veins at the sites of injection.
SubQ injection (“skin popping”) - multiple, scattered ulcerations, which heal with discrete atrophic scars
Cutaneous manifestation include camptodactylia, edema of the eyelids, persistent nonpitting edema of the hands, urticaria, abscesses, atrophic scars, and hyperpigmentation
- Cocaine - cause ulcers because of its direct vasospastic effect
- Penrazocine - typical clinical picture of tense woody fibrosis, irregular punched-out ulcerations, and a rim of hyperpigmentation at injection sites. Extensive calcification may occur within the thickened sites.
Classification of burn when it involves loss of tissue of the full thickness and some of the subcutaneous tissues
Third-degree (full thickness) burns
Classification of burn when it involves loss of tissue of the full thickness and some of the subcutaneous tissues
Third-degree (full thickness) burns
Characterization of different regions of burns also can be described as the
Zone of Hyperemia
Zone of Stasis
Zone of Coagulation
Rubbing pigmented lesions elicit wheeling seen in Systemic Mastocytosis
Darier’s Sign
Condition is distributed along the lines of Blaschko
Epidermal Nevi
Most common cause of radiation cancer
Basal cell CA
Intermittent intense sun exposure, as identified by prior sunburns; radiation therapy; a positive family history of BCC; immunosuppression; a fair complexion, especially red hair; easy sunburning (skin types I or II); and blistering sunburns in childhood are risk factors for the development of BCC. Indoor tanning is a strong risk factor for early-onset BCC, particularly among women. The classic or nodular BCC constitutes 50%–80% of all BCCs.
Most common internal systemic cause of pruritus
Chronic Kidney Disease - most common systemic cause of pruritus; 20%–80% of patients with chronic renal failure have itching
The most important internal causes of itching include liver disease, especially obstructive and hepatitis C (with or without evidence of jaundice or liver failure), renal failure, diabetes mellitus, hypothyroidism and hyperthyroidism, hematopoietic diseases (e.g., iron deficiency anemia, polycythemia vera), neoplastic diseases (e.g., lymphoma [especially Hodgkin disease and cutaneous T-cell lymphoma], leukemia, myeloma), internal solid-tissue malignancies, intestinal parasites, carcinoid, multiple sclerosis, acquired immunodeficiency syndrome (AIDS), connective tissue disease (particularly dermatomyositis) and neuropsychiatric diseases, especially anorexia nervosa.
Russell’s sign which is crusted papules at the dorsa of the dominant hand from cuts by the teeth
Bulimia
with its self-induced vomiting, results in Russell sign—crusted papules on the dorsum of the dominant hand from cuts by the teeth. Clenching of the hand produces swelling and ecchymosis of the fingertips and subungual hemorrhage.
Self-biting may be manifested by biting the nails (_________________) or recurrent manipulation of components of the nail unit (_________________)
Self-biting may be manifested by biting the nails (onychophagia) or recurrent manipulation of components of the nail unit (onychotillomania)
“matchbox” or “ziplock” sign (Samples of alleged parasites enclosed in assorted containers, paper tissue, or sandwiched between adhesive tape)
Delusional infestation (Ekbom syndrome or Delusions of Parasitosis)
firm fixation in a person’s mind that he or she suffers from a parasitic infestation of the skin. Usually, the only symptom is pruritus or a stinging, biting, or crawling sensation. Intranasal formication, or a crawling sensation of the nasal mucosa, is common in this condition. Pimozide was the long-standing treatment of choice given at relatively low dosages, in the 1–4 mg range.
most common cause of primary cicatricial (scarring) alopecia
LICHEN PLANOPILARIS
Graham-Little syndrome is a very rare condition that predominantly affects female adults. It is characterized by LPP of the scalp, noncicatricial of the eyebrows, axilla, and groin, and keratosis pilaris. The most likely drugs to cause lichenoid drug eruption are quinine and thiazide diuretics. First-line treatment for moderately active classic LPP lesions is intralesional triamcinolone acetonide at a concentration of 10 mg/mL every 4 to 6 weeks or in combination with topical class I or class II corticosteroids.
most common form of primary cicatricial alopecia in women of African descent
CENTRAL CENTRIFUGAL CICATRICIAL ALOPECIA
common cause of hair loss in children secondary to an infection with dermatophytes species
Tinea capitis (Trichophyton tonsurans)
Ectothrix infection - most commonly caused by Microsporum spp. (especially Microsporum canis) and Epidermophyton spp. destroy the hair cuticle and masses of spores are located outside of the hair shaft.
Yellow-green under Woods Lamp
Endothrix infection - most commonly caused by Trichophyton spp. (especially T. tonsurans subspecies sulfureum). The hair breaks off directly at the skin surface, which clinically presents as “black dots.”
Favus is a specific type of tinea capitis characterized by patelliform scales (scutula), which are sulfuric-yellow concretions of hyphae and skin debris in the follicular orifices and exhibit a distinct malodorous smell. A kerion is a deep, highly inflammatory fungal infection of the scalp. It presents as a highly suppurative, boggy, nodular, deep folliculitis with fistulas and pus secretion. Favus and kerion may lead to scarring hair loss and should be treated aggressively.
“Friar-Tuck” form of vertex and crow alopecia
Trichotillomania
form of traumatic alopecia caused by an irresistible compulsion to pull out or twist or break of one’s own hair.
Flat topped , red to brown pruritic papules that spares the skin folds producing bands of unoinvolved cutis seen in Papuloerythroderma of Ofuji
Deck-chair sign,
Unilateral nipple eczema is more than 3 months
Paget’s disease of the breast
Most commonly affected sites: unilateral nipple/ areola (mammary Paget’s disease [MPD]); vulva, perianal skin, scrotum, and penis (extramammary Paget’s disease [EMPD]).
Mammary Paget’s disease (MPD; also called Paget’s disease of the breast) is an intraepidermal adenocarcinoma of the nipple and/or areola, typically associated with underlying breast carcinoma. Extramammary Paget’s disease (EMPD) is a clinically distinct condition that affects extramammary sites, such as the vulva, penis, scrotum, perineum, and anus.
Malum perforans pedis NOT seen
Hansens Disease
Seen in Late (Parenchymatous) Neurosyphilis. Tabes dorsalis is the degeneration of the dorsal roots of the spinal nerves and of the posterior columns of the spinal cord. Gastric crisis with severe pain and vomiting is the most frequent symptom. The signs that may be present are Argyll Robertson pupils, absent or reduced reflexes, Romberg sign, deep tendon tenderness, loss of proprioception and vibratory sensation, atonic bladder, trophic changes, malum perforans pedis, Charcot joints, and optic atrophy.
Major features of Atopic dermatitis (PEFF)
AD is a chronic or chronically relapsing disorder with major features of:
■ Pruritus
■ Eczematous dermatitis (acute, subacute, or chronic) with typical morphology and agespecific patterns
■ Facial and extensor involvement in infancy
■ Flexural eczema or lichenification in children and adults
Commonly associated with the following:
■ Personal or family history of atopy (allergic rhinitis, asthma, atopic dermatitis)
■ Xerosis or skin barrier dysfunction
■ Immunoglobulin E reactivity
Pathogenesis driven by skin barrier defects (most importantly in the FLG gene), environmental effects and alterations in immunologic responses in T cells, antigen processing, inflammatory cytokines, host defense proteins, allergen sensitivity, and infection
Thinning or loss of the lateral third eyebrows seen in atopic dermatitis (also seen in seborrhoeic dermatitis) due to continuous scratching
Hertoghe’s sign
Management of Eczema herpeticum (Kaposi Varicelliform Eruption)
IV or oral Antivirals (Acyclovir, 400 mg orally three times daily; famciclovir, 500 mg twice daily; or valacyclovir, 1 g twice daily, all for a minimum of 5–10 days, is used.)
The three clinical hallmarks of HSV infection are pain, an active vesicular border, and a scalloped periphery.
Atopic Dermatitis with lesions on eyelids and face and areas prone to atrophy managed with
Corticosteroids (like hydrocortisone) applied to your skin.
Oral (taken by mouth) corticosteroids.
Topical Calcineurin inhibitors
Cornerstone of treatment for mild AD and serve as an important flare preventive therapy for all levels of disease severity.
Emollients
Patients with AD have abnormal skin barrier function with increased transepidermal water loss and decreased water content and dry skin (xerosis) contributing to disease morbidity by the development of microfissures and cracks in the skin. The daily use of an effective emollient helps to restore and preserve the stratum corneum barrier, decreases the need for topical glucocorticoids and NSAIDs and improves outcomes.
cornerstone of antiinflammatory treatment in AD
Topical Corticosteroids
use topical glucocorticoids only to control acute exacerbations of AD.
Most common topical medication may cause allergic contact dermatitis and cause ear eczema
Topical Neomycin and Bacitracin
gold standard for identification of the allergen or allergens causing ACD
Patch testing
With this protocol the allergens are placed on the back under occlusion, removed at 48 hours, and a final delayed read is performed at 72 or 96 hours. The International Contact Dermatitis Research Group recommends using the grading scale for positive patch test reactions outlined by Wilkinson and colleagues, 114 which is a + to +++ scoring system, where + represents a weak nonvesicular reaction but with palpable erythema, ++ represents a strong (edematous or vesicular) reaction, and +++ represents an extreme (bullous or ulcerative) reaction
Metal that causes earlobe dermatitis (earlobe eczema)
Nickel
Nickel is the most frequently patch test-positive allergen worldwide, with sensitization rates that hover mostly in the range of 18% to 30%.76
Multiple vesicles at the sides of the fingers resembling tapioca
Dyshidrotic Eczema (Dyshidrosis or Pompholyx)
Vesiculobullous Hand Eczema (Pompholyx, Dyshidrosis). Primary lesions of dyshidrosis are deep-seated multilocular vesicles resembling tapioca on the sides of the fingers, palms, and soles. The eruption is symmetric and pruritic, with pruritus often preceding the eruption. Coalescence of smaller lesions may lead to bulla formation severe enough to prevent ambulation.
Potent and ultrapotent topical corticosteroids are first-line pharmacologic therapy.
Example of a topical calcineurin inhibitor
Tacrolimus and cyclospirin
Topical calcineurin inhibitors (TCIs) work by altering the immune system and have been developed for treating atopic eczema. There are two types available: tacrolimus ointment (Protopic) for moderate to severe eczema and pimecrolimus cream (Elidel) for mild to moderate eczema.
SE: nephrotoxicity
Coin-shaped vesicular lesions on the extensors of arms
Nummular Dermatitis
Appearance of lesions at areas of trauma
Koebner’s phenomenon
Irritant in hot pepper
Capsaicin
Hand irritation produced by capsaicin in hot peppers used in Korean and North Chinese cuisine (Hunan hand) may be severe and prolonged, sometimes necessitating stellate ganglion blockade and gabapentin. Pepper spray, used by police in high concentrations and by civilians in less concentrated formulas, contains capsaicin and may produce severe burns.
Acetic acid 5% (white vinegar) or antacids (Maalox) may completely relieve the burning, even if applied an hour or more after the contact.
Type of hypersensitivity reaction is allergic contact dermatitis
Type IV
ACD represents a classic cell-mediated (type IV), delayed hypersensitivity reaction. Type IV hypersensitivity reactions result from exposure and sensitization of a genetically susceptible host to an environmental allergen, followed by subsequent reexposure that triggers a complex inflammatory reaction
When is patch test initially removed
48H
With this protocol the allergens are placed on the back under occlusion, removed at 48 hours, and a final delayed read is performed at 72 or 96 hours.
Black dermographism is due to
Zinc Oxide
Black Dermatographism. Black or greenish staining under rings, metal wristbands, bracelets, and clasps is caused by the abrasive effect of cosmetics or other powders containing zinc or titanium oxide on gold jewelry. This skin discoloration is black because of the deposit of metal particles on skin that has been powdered and that has metal, such as gold, silver, or platinum, rubbing on it. Abrasion of the metal results because some powders are hard (zinc oxide) and can abrade the metal.
HLA type of those with Carbamazepine-induced SJS/TEN
HLA B*1502
HLA-B*1502 is present in the vast majority of carbamazepineinduced SJS/TEN patients
SJS is defined as <10% epidermal detachment, TEN as >30% epidermal detachment, and SJS/TEN overlap as 10%–30% detachment, measured at the worst extent of the disease.
Average time for epidermal regrowth for patients with SJS/TEN
3 weeks
the average time for epidermal regrowth is 3 weeks. The most common sequelae are ocular scarring and vision loss. The only predictor of eventual visual complications is the severity of ocular involvement during the acute phase. A sicca-like syndrome with dry eyes may also result, even in patients who never had clinical ocular involvement during the acute episode.
Most common cause of nonimmunologic urticaria
Aspirin and NSAIDs
Aspirin and NSAIDs are the most common causes of nonimmunologic urticarial reactions. They alter prostaglandin metabolism, enhancing degranulation of mast cells.
Urticarial drug eruptions are the second most common type of cutaneous adverse drug eruption, and can be induced by immunologic and nonimmunologic mechanisms.
Immunologic urticaria is most often associated with
penicillin and related β-lactam antibiotics
often used for depression and smoking cessation. It can induce urticaria, which may be severe and associated with hepatitis and a serum sickness like syndrome
Bupropion
Two antihistamines may induce urticaria
cetirizine and hydroxyzine
known complication of the use of ACE inhibitors and angiotensin II antagonists
Angioedema
Lisinopril and enalapril produce a edema more frequently than captopril
Red Man Syndrome
IV infusion of vancomycin
Spectrum that triggers most medication-related photosensitivity
UVA
Drug causes blue or brown pigmentation in the lunula or whole nail plate
Zidovudine
Zidovudine causes a blue or brown hyperpigmentation that is most frequently observed in the nails. The lunula may be blue, or the whole nail plate may become dark brown.
Clofazimine - appearance of a pink discoloration that gradually becomes reddish blue or brown and is concentrated in the lesions of patients with Hansen disease. Histologically, a PAS-positive, brown, granular pigment is variably seen within foamy macrophages in the dermis. This has been called “drug-induced lipofuscinosis.”
Chlorpromazine, thioridazine, imipramine, and clomipramine may cause a slate-gray hyperpigmentation in sun-exposed areas after long periods of ingestion. Frequently, corneal and lens opacities are also present
Amiodarone - photosensitivity
Chloroquine, hydroxychloroquine, and quinacrine - blue-black pigmentation of the face, extremities, ear cartilage, oral mucosa, and nails, in up to 29% of patients. Pretibial hyperpigmentation is the most common pattern.
Physical sunscreens
zinc oxide or titanium dioxide
Vitamin D supplementation is recommended with the most stringent sun protection practices. The dose is 600 IU daily for those 70 and younger and 800 IU for older patients.
What is the most common cause of SJS in children
Mycoplasma pneumoniae
high-risk drugs are antibacterial sulfonamides, aromatic antiepileptic drugs, allopurinol, oxicam nonsteroidal antiinflammatory drugs, lamotrigine, and nevirapine. most inducing medications revealed the first continuous exposure between 4 and 28 days before reaction onset.
Which medication may induce Pemphigus
Captopril and Penicillamine
EM minor (skin and lips only) is associated with
HSV
EM minus (EMm, also called EM minor) if only the skin and lips are involved and EM majus (EMM, also called EM major) when mucous membranes are affected
■ Erythema multiforme is a rare cutaneous or mucocutaneous eruption characterized by “target” lesions, predominantly on the face and extremities.
■ The highest incidence was found in male children and young adults.
■ Most cases are related to infections (herpes simplex virus [HSV] and Mycoplasma pneumoniae).
A total of 66% of EM patients have HLA-DQB1 ∗ 0301 allele
This condition is characteristically concentric with wood grain appearance.
Erythema gyratum repens
■ Usually a paraneoplastic phenomenon.
■ Characteristic wood grain appearance with multiple concentric rings.
Necrolytic migratory erythema resembles
Zinc deficiency
As necrolytic migratory erythema is considered a deficiency dermatosis, the repletion of various nutrients has been utilized in the literature to target this entity specifically. In particular, supplementation of zinc, essential fatty acids, and amino acids have been shown in some cases to resolve NME.
NME is a very rare paraneoplastic skin disorder that is considered a hallmark of glucagonoma.
■ Painful, eroded, crusted intertriginous, and facial skin eruption.
■ Highly suggestive of pancreatic malignancy (Glucagonoma is an extremely rare, slow-growing neuroendocrine tumor of the α cells of the pancreas).
Deep seated vesicle-like papules resembling frog spawn seen at birth
Microcystic Lymphatic Malformation (Lymphangioma Circumscriptum)
a congenital malformation of the superficial lymphatics. An MLM presents as groups of deep-seated, vesicle-like papules, resembling frog spawn, at birth or shortly thereafter.
The sites of predilection are the abdomen, axillae, genitalia, and mouth, particularly the tongue.
Sweet’s syndrome is associated with this hematologic malignancy
acute myelogenous leukemia (AML)
Sweet’s syndrome is an acute febrile neutrophilic dermatosis in which approximately 20% of the reported patients have an associated cancer.
The most common underlying neoplasm was acute myelogenous leukemia (AML)
Sweet syndrome may occur with myelodysplastic syndromes or with hemoproliferative malignancies including leukemias (usually acute myelogenous) and lymphomas. One study reported an increased frequency of FLT3 mutations or del(5q) karyotype in AML patients with Sweets. Solid tumors are of any type but are most often genitourinary, breast (in women), or gastrointestinal (in men). Anemia is found in 93% of men and 71% of women with malignancy-associated Sweet syndrome.
The majority of cases of Sweet syndrome follow a URI or viral gastroenteritis
This condition presents with acute onset of plaques resembling cellulitis and histologically with plenty of eosinophils producing flame figures
Wells syndrome or eosinophilic cellulitis
acute onset of plaques resembling cellulitis that persisted for many weeks. Degranulation of dermal eosinophils produces the flame figures seen in histologic sections. These consist of dermal collagen with adherent eosinophil granules. Eosinophilic panniculitis may also be present. The most frequent systemic complaint in patients with Wells syndrome is malaise
■ Peripheral blood eosinophilia common.
■ Histologic pattern characterized by dermal infiltration with eosinophils, and flame figures surrounded by histiocytes.
■ Systemic glucocorticoids usually therapeutic.
The mainstay for treatment of chronic urticaria
H1 antihistamines (terfenadine, astemizole, loratadine, and cetirizine hydrochloride)
% of DLE that remains confined to the skin
95%
Discoid lupus erythematosus (DLE) begin as dull-red macules or indurated plaques that develop an adherent scale, then evolve with atrophy, scarring, and pigment changes. The hyperkeratosis characteristically extends into patulous follicles, producing carpet tacklike spines on the undersurface of the scale.
Classical discoid lupus erythematosus causes scarring and can be permanently disfiguring. Subacute cutaneous lupus and acute cutaneous lupus erythematosus are highly photosensitive and are characteristically nonscarring.
Treatment consists of physical sun protection, topical sunscreens, local and short-term systemic glucocorticoids, antimalarials, retinoids, thalidomide/lenalidomide, conventional immunosuppressives, and biologic therapies.
Both systemic lupus erythematosus and cutaneous lupus erythematosus are associated with upregulation of type 1 interferon signaling.
En coup de sabre is localized scleroderma located at the
frontoparietal area of the head (forehead)
Linear scleroderma “en coup de sabre” (LScs) denotes linear scleroderma of the frontoparietal area of the head. Lesions may also occur parasagittally on the frontal scalp and extend partly down the forehead (en coup de sabre
“Dry riverbed sign” is a finding in
EOSINOPHILIC FASCIITIS
Classically, patients had engaged in strenuous muscular activity for a few days or weeks before the acute onset of weakness, fatigability, and pain and swelling of the extremities. The skin is usually edematous and erythematous, with a coarse peau d’orange appearance, and a “pseudocellulite” appearance most noticeable inside the upper arms, thighs, or flanks. The hands and face are usually spared. When the patient holds the arms laterally or vertically, linear depressions occur within the thickened skin. This “groove sign” or “dry riverbed sign” follows the course of underlying vessels
Alopecia mucinosa maybe an initial manifestation of
Mycosis fungoides
FOLLICULAR MUCINOSIS (ALOPECIA MUCINOSA)
characterized by inflammatory plaques with alopecia that demonstrate mucinous deposits in the outer root sheath of the hair follicle on histopathology. The plaques may be simply hypopigmented or erythematous and scaly, eczematous, or composed of flesh-colored, follicular papules. The disease may be limited to skin and benign (primary follicular mucinosis) or may be associated with follicular mycosis fungoides.
Hydroxychloroquine is an excellent first-line systemic therapy.
Rheumatoid nodules are usually located on
bony prominences, especially on the extensor surface of the forearm
Subcutaneous nodules are seen in 20%–30% of patients. They may arise anywhere on the body but most frequently are found over the bony prominences, especially on the extensor surface of the forearm just below the elbow and the dorsal hands. The lesions are nontender, firm, skin-colored, round nodules, which may or may not be attached to the underlying tissue. Accelerated RN may occur with the appearance of multiple RNs, typically following initiation of a treatment for RA, most commonly methotrexate
heals with bruise like patches
Erythema nodosum
Erythema nodosum (EN) is the most common inflammatory panniculitis. The eruption consists of bilateral, symmetric, deep, tender nodules and plaques 1–10 cm in diameter. The most common location is the pretibial area and lateral shins.
Over a few days, the lesions flatten, leaving a purple or blue-green color resembling a deep bruise (erythema contusiforme).
It is frequently associated with a streptococcal infection (especially in children).
EN is frequently seen in patients with inflammatory bowel disease (IBD), more often Crohn disease than ulcerative colitis
Drugs may also induce EN. Currently, oral c tives, hormone replacement therapy, sulfonamides, and penicillins are the most common medications inducing EN.
The removal of scales resulting in bleeding points is
Auspitz’s sign
Hanging curtain sign
Pityriasis rosea
Pityriasis rosea is a mild inflammatory exanthem characterized by salmon-colored thin papules and plaques that are at first discrete but may become confluent. The individual patches are oval or circinate and covered with finely crinkled, dry epidermis, which often desquamates, leaving a collarette of scaling in the center. When stretched across the long axis, the scales tend to fold across the lines of stretch, the so-called hanging curtain sign or Christmas tree sign.
The most commonly implicated viruses are herpes viridae such as human herpesvirus (HHV)–6 and HHV-7.
A pityriasis rosea–like eruption may occur as a reaction to medications such as captopril, imatinib mesylate, interferon, ketotifen, arsenicals, gold, bismuth, clonidine, methoxypromazine, tripelennamine hydrochloride, ergotamine, lisinopril, acyclovir, lithium, adalimumab, nortriptyline, lamotrigine, rituximab, imatinib, asenapine, barbiturates, or bacille Calmette-Guérin (BCG) vaccine.
Most patients with pityriasis rosea require no therapy because they are asymptomatic, however, use of acyclovir with multiple trials showing decrease the eruption and itching.
Characteristic nail finding in Lichen planus
Irreversible pterygium
Ultrapotent topical and intralesional corticosteroids (5 to 10 mg/mL injected on a weekly basis) are firstline therapies.
Lichen planus (LP) is a common, pruritic, inflammatory disease of the skin, mucous membranes, and hair follicles. The primary lesions of LP are characteristic, almost pathognomonic: small, flat-topped, polygonal papules. On the surface, gray or white puncta or streaks (Wickham striae) cross the lesions—a feature seen more easily with dermoscopy.
Nail changes are present in approximately 5%–10% of patients with fingernails more often affected than toenails. Involvement of the nail can occur as an initial manifestation, especially in children. Longitudinal ridging and splitting are most common, seen in 90% of patients with nail involvement. Onycholysis and subungual debris may be present, indicating involvement of the nail bed. The lunulae are red in 30% of patients with nail LP. Involvement of the entire matrix may lead to obliteration of the whole nail plate (anonychia). Pterygium formation is characteristic of LP of the nails, but seen in only about 20% of patients.
The most common location of lesions of Necrobiosis lipoidica (skin disorders in DM)
Anterior Shin
NECROBIOSIS LIPOIDICA/NECROBIOSIS LIPOIDICA DIABETICORUM
Necrobiosis lipoidica (NL) is characterized by well-circumscribed, firm, depressed, waxy, yellow-brown plaques, usually of the anterior shin.
The earliest changes are small, sharply bordered, red papules that may be capped by a slight scale and that do not disappear under diascopic pressure. Later, the lesions develop into irregularly round or oval lesions with well-defined borders and a smooth, glistening (glazed) surface. The most common location of the lesions is the shins
Roseola infantum or Exanthem subitum is usually due to
HHV 6
Causes exanthem subitum (roseola infantum, sixth disease). β-Herpesviridae subfamily. The hallmark of ES is the development of “rose”-colored macules and papules measuring 2 to 5 mm and surrounded by a white halo. The exanthem lasts 3 to 5 days and is widespread spread on the neck and trunk.
High seroprevalence in general population by 1 year of age. HHV-6 is a common viral infection with up to 80% of the population acquiring the infection by 2 year of age.
Reactivation in immunocompromised individuals is a cause of morbidity. HHV-6 transmission occurs via shared saliva and can readily be detected in the saliva of adults and children.
The incubation period for HHV-6 infection is 5 to 15 days, with an average of 10 days.
Prophylaxis with ganciclovir may prevent HHV-6 reactivation in bone marrow transplantation and stem cell transplantation recipients, but low-dose prophylaxis may facilitate the development of resistance.
Vesicles on the side and tip of the nose seen in Opthalmic zoster
Hutchinson sign
In herpes zoster ophthalmicus, the ophthalmic division of the fifth cranial nerve is involved. If the external division of the nasociliary branch is affected, with vesicles on the side and tip of the nose (Hutchinson sign). Ocular involvement is most often in the form of uveitis (92%) and keratitis (50%).
Most cases of Malignant Acanthosis nigricans is due to
adenocarcinoma of the stomach
Most cases are associated with adenocarcinoma, especially of the gastrointestinal tract (60% stomach). Type I AN should be highly suspected if widespread lesions develop in a nonobese man over age 40. Tripe palms (acanthosis palmaris) are characterized by thickened, velvety palms with pronounced dermatoglyphics. In 40% of these patients, tripe palms are the presenting sign of an undiagnosed malignancy.
Acanthosis nigricans (AN) is characterized by hyperpigmentation and velvet-textured plaques, which are symmetrically distributed.
In acrodermatitis enteropathica,supplementation with
zinc is at a dose of 1 – 2 mg/kg/day
Replacement is with zinc sulfate, 1–2 mg/kg/day (50 mg of elemental zinc per 220 mg zinc sulfate tablet). In patients with genetic causes of acrodermatitis enteropathica, zinc supplementation is 3 mg/ kg/day and should be lifelong.
Zinc deficiency may be an inherited abnormality, acrodermatitis enteropathica, or it may be acquired. Acrodermatitis enteropathica is an autosomal recessive disorder caused by mutations in the SLC39A4 gene, which encodes the zinc transporter ZIP4.
The diagnosis of zinc deficiency should be suspected in at-risk individuals with acral or periorificial dermatitis. In particular, chronic diaper rash with diarrhea in an infant should lead to evaluation for zinc deficiency
a disease of the apocrine glands
Hidradenitis suppurativa (acne inversa)
chronic disease characterized by recurrent abscess formation, primarily within the folded areas of skin that contain both terminal hairs and apocrine glands. The primary site of inflammation terminal hair. The axilla is the most frequently affected site. HS is characterized by recurrent, deep-seated, painful, subcutaneous nodules, sinus tracts, and hypertrophic scarring.
■ Lesions are characterized by inflammatory nodules, subcutaneous abscesses, and sinus tracts.
■ Hyperkeratotic plugging of the terminal hair follicle is a consistent histologic finding of early disease and is thought to be the primary pathophysiologic event. The microbiome is altered and secondary bacterial infection with S. aureus, Streptococcus pyogenes, and various gramnegative organisms may occur.
Daily cleansing with chlorhexidine gluconate (Hibiclens) solution or benzoyl peroxide wash is an important preventive measure.
The drug of choice for Leishmaniasis
Pentavalent antimony
■ Leishmaniasis is a complex of diseases caused by the protozoa Leishmania and transmitted by the bite of infected phlebotomine sandflies. leishmaniasis is the third most frequent infectious disease transmitted by a vector.
■ Four major human diseases: (a) localized cutaneous leishmaniasis, (b) diffuse cutaneous leishmaniasis, (c) mucocutaneous leishmaniasis, and (d) visceral leishmaniasis.
The main reservoir hosts are the great gerbil, the fat sand rat, Meriones spp., and other rodents, as well as dogs, the opossum, sloths, and others.
The drug of choice for Leishmaniasis
Pentavalent antimony
The drug of choice for Leishmaniasis
Pentavalent antimony
Slapped cheek appearance
Fifth disease – Erythema infectiosum
Parvovirus B19 is the most common agent in this Erythrovirus genus to cause human disease. Erythema infectiosum is a worldwide benign infectious exanthem that occurs in epidemics in the late winter and early spring.
Erythema infectiosum (fifth disease): childhood illness with “slapped cheeks” followed by an erythematous, lacy eruption on the trunk and extremities.
■ Symmetric polyarthritis, particularly of the small joints in adults.
■ Papular purpuric gloves-and-socks syndrome: pruritic erythema, edema, and petechiae of the hands and feet, fever, and oral erosions in adolescents. occurs primarily in teenagers and young adults.
■ Aplastic crisis in patients with increased red blood cell turnover, chronic anemia in immunocompromised persons, and fetal hydrops.
This type of onychomycosis (Tinea Unguium) is usually associated with chronic paronychia
Candida
Onychomycosis is defined as the infection of the nail plate by fungus and represents up to 30% of diagnosed superficial fungal infections. T. rubrum accounts for most cases.
four classic types of onychomycosis:
1.) Distal subungual onychomycosis - distal nail bed and the hyponychium
2.) White superficial onychomycosis (leukonychia trichophytica) - toenail plate. In the HIV-positive population, it is typically caused by T. rubrum.
3.) Proximal subungual onychomycosis - proximal nailfold. It is produced by T. rubrum and Trichophyton megninii and may be an indication of HIV infection.
4.) Candida - destruction of the nail and massive nail bed hyperkeratosis. It is caused by C. albicans and is seen in patients with chronic mucocutaneous candidiasis
tender subcutaneous nodules commonly located on the posterior calves
Erythema induratum (Bazin disease - back calf)
Lesions favor the posterior lower calf, which may also show acrocyanosis. Individual lesions are tender, erythematous or violaceous, 1–2 cm subcutaneous nodules
Biopsy with acid-fast staining should be done when the history and physical examination suggest cutaneous TB.
For all forms of cutaneous TB, multidrug chemotherapy is recommended.
DIF findings of Linear C3 and IgG at BMZ
Bullous pemphigoid
IgG and/ or C3 are best found in nonbullous lesional or perilesional skin.
Clinically, BP is characterized by large, tense, subepidermal bullae with a predilection for the groin, axillae, trunk, thighs, and flexor surfaces of the forearms
BP230 and BP180. BP may begin at a localized site, frequently on the thighs or shins.
vesicular pemphigoid - tense, small, occasionally grouped
pemphigoid nodularis - resembling prurigo nodularis
pemphigoid vegetans - IgG and C3 at the BMZ
lichen planus pemphigoides - lichen planus. Linear IgG and C3 are noted at the BMZ
String of pearls configuration
Chronic bullous disease of childhood
Chronic bullous disease of childhood (CBDC) is an acquired, self-limited bullous disease that may begin by the time the patient is 2 or 3 years old and usually remits by age 13. Bullae are often arranged in rosettes or an annular array, the so-called string of pearls configuration. Pruritus is often severe.
presence of a subepidermal bulla filled with NEUTROPHILS.
DIF reveals a linear deposition of IgA at the BMZ
Ocular pemphigus with essential shrinkage of conjunctiva
Cicatricial pemphigus (C for conjunctiva)
ocular pemphigus, cicatricial pemphigoid, or essential shrinkage of the conjunctiva. Because of its scarring nature, the designation cicatricial pemphigoid (CP) has gained predominance
In most patients, the vesicles primarily occur on the mucous membranes, especially the conjunctiva
Cyclophosphamide or rituximab-containing regimens are generally advised.
Ulcers on the legs caused by Group A Beta hemolytic streptococci pyogenes
Ecthyma
Ecthyma is an ulcerative streptococcal or less commonly staphylococcal pyoderma. The disease begins with a vesicle or vesicopustule, which enlarges and in a few days becomes thickly crusted. When the crust is removed, there is a superficial, saucer-shaped ulcer with a raw base and elevated edges
Ecthyma gangrenosum is caused by
P. aeruginosa
opalescent, tense vesicles or pustules are surrounded by narrow, pink to violaceous halos. These lesions quickly become hemorrhagic and violaceous and rupture to become round ulcers with necrotic black centers.
Ecthyma gangrenosum occurs in debilitated persons who may be suffering from leukemia, in the severely burned patient, in pancytopenia or neutropenia, or in patients with a functional neutrophilic defect, terminal carcinoma, or other severe chronic disease.
Recommended treatment is the immediate institution of IV antipseudomonal penicillin.
Erythrasma Caused by ________ usually in the intertriginous areas,
Corynebacterium minutissimum
Erythrasma is characterized by sharply delineated, dry, brown, slightly scaling patches occurring in the intertriginous areas, especially the axillae, the genitocrural crease, and the webs between the fourth and fifth toes and less often the third and fourth toes.
The Wood’s light is the diagnostic medium for erythrasma. The affected areas show a coral-red fluorescence, which results from the presence of a porphyrin.
Topical erythromycin
