• Information
  1. Evaluation of Dermatologic Lesions
  2. Definitions
  3. Bullae
  4. Vesicles
  5. Purpura
  6. Common Dermatologic Findings

• MISCELLANEOUS DERMATOLOGIC CONDITIONS
  1. Erythromelalgia
  2. Ichthyosis
  3. Sweet's Syndrome

A. Evaluation of Dermatologic Lesions

1. There are over 1000 distinct dermatologic entities
   1. There are <20 distinct skin lesions
   2. Goal is to classify major lesion(s) to limit differential diagnosis
2. Consider accompanying symptoms, including systemic complaints
3. Major Lesion Types
   1. Bullae
   2. Vessicles
   3. Purpura
   4. Plaques - consider psoriasis
   5. Waxy Lesions - seborrheic dermatitis
   6. Pruritic Lesions - atopic dermatitis
   7. Scales - type and pattern of scales
   8. Target Lesions
   9. Erythromelalgia
4. Examination of hair, nails, mucous membranes is part of dermatologic evaluation

B. Definitions

1. Macule: flat lesion on skin (neither elevated nor depressed)
2. Papule: small solid elevation <0.5cm diameter
3. Plaque: raised or depressed lesion >0.5cm diameter
4. Wheal: whelt; circumscribed area of edema of skin, usually red, usually pruritic
5. Nodule: a small (<0.5cm), raised, solid, circular structure, penetrates into dermis
6. Vesicle: small, raised circumscribed elevation of skin (blister) containing fluid
7. Bullae: a large vesicle (>0.5cm) with circumscribed area of separation from epidermis
8. Erosion: shallow ulcer, generally without bleeding
9. Pustule: vesicle containing dead neutrophils and bacteria (pus)
10. Petechiae: due to capillary rupture/bleeding, 1-3mm purple macules
11. Hyperkeratosis
    1. Increase in thickness of stratum corneum; seen as a scale
    2. May retain basketweave pattern, or become dense and compact
12. Papillomatosis
    1. Epidermal and papillary dermal proliferation upward
    2. Occurs in irregular waves or spikes
13. Parakeratosis: retention of keratinocytic nuclei in stratum corneum
14. Squamous eddies (pearls): concetric layers of squamous cells with increasing central keratinization
15. Verrucous (Verrucose): resembling a wart; roughened, irregular or filiform surface

C. Bullae

1. Upper Epidermis
   1. Pemphigus Vulgaris
   2. Scalded Skin Syndrome (Staphylococcal)
2. Subepidermal
   1. Erythema Multiforme
   2. Stevens-Johnson Syndrome
   3. Toxic Epidermal Necrolysis
   4. Bullous Pemphigoid
   5. Herpes Gestationes
   6. Cicatricial pemphigoid
   7. Lupus erythematosus

D. Vesicles

1. VZV
   1. Chicken Pox
   2. Shingles
2. Contact Dermatitis
3. Dermatitis Herpetiformis
4. Herpes simplex virus (HSV)
5. Drug eruption

E. Purpura

1. Definition: non-blanching erythema
2. Palpable Purpura
   1. Rocky Mountain Spotted Fever
   2. Meningococcemia and Gonococcemia
   3. Bacterial Endocarditis
   4. Obliterative Vasculitis - cryoglobulinemia, hypersensitivity vasculitis, others
   5. Drug Reaction
   6. Atrial Myxoma
3. Non-Palpable Purpura
   1. Disseminated Intravascular Coagulopathy (DIC)
   2. Scurvy [1]
   3. Purpura due to anticoagulants
   4. Glucocorticoid (steroid) induced purpura
   5. Senile purpura
4. Vasculitis
   1. Inflammation of blood vessel walls
   2. Extravasation of blood and inflammatory cells into surrounding tissue
   3. ANCA Related: PAN, Wegener's Granulomatosis, Behcet's Disease, others
   4. Henoch-Schonlein Purpura and Hypersensitivity
   5. Infectious, associated with immune complexes: bacterial endocarditis, others
   6. Occlussive Disease: Cryoglobulinemia, Cholesterol Emboli,
   7. Most of these cause a palpable purpura
   8. Disseminated Intravascular Coagulopathy (DIC) often causes a non-palpable purpura

F. Common Dermatologic Findings

1. Common Acne
2. Rosacea
3. Psoriasis
4. Hives
5. Nail Changes
6. Xanthelasma
   1. Bright yellow, sharply marginated plaques
   2. Usually on eyelids, may also occur on external ear areas
   3. Usually found in patients with lipid disorders
7. Seborrheic Dermatitis
   1. Waxy, inflammatory dermatitis
   2. Waxy scales, "dandruff", redness in nasolabial fold and eyebrows
   3. Most common in persons 30-60 years of age
8. Eczematous Dermatitis
   1. Definition: ill defined erythematous scaly plaques ± pruritus
   2. Erythema with irritation and dryness
   3. Pruritus may be prominent; localized edema
9. Actinic Keratosis (AK) [2]
   1. Synonyms: Solar Keratosis, Solar Elastosis, Senile Keratosis
   2. Types: Pigmented AK and Non-pigmented AK
   3. Rough, faintly erythematous, slightly raised skin lesions
   4. Most frequently on face and hands (sun exposed area)
   5. Overall very slow progression to frank invasive cancer
   6. ~1:1000 progress each year to squamous cell cancer
10. Cafe-au-lait Spots (Macules)
    1. Found in ~10% of normal persons
    2. Neurofibromatosis (NF) - diagnostic for NF if >5 macules with diameter >1.5 cm
    3. Polyostotic Fibrous Dysplasia (Albright's Syndrome)
11. Dermatophytosis [6]
    1. Superficial fungal infections - erythematous and scaly
    2. Fungal mycelia detected by exam of material from border of rash
    3. Diagnosis made with KOH (potassium hydroxide) preparation of skin scarping
    4. Athlete's Foot - Tinea pedis
    5. Jock Itch - Tinea cruris
    6. Scalp Infection - Tinea capitis
    7. Tinea versicolor (pityriasis versicolor) - pigmentary disorder, usually in tropics
    8. Piedra - asymptomatic fungal infection of hair shaft
    9. Tinea nigra - common in tropical regions outside of US and Europe
12. Melasma (Chloasma)
    1. Hyperpigmentation usually on face
    2. Associated with pregnancy and/or taking progestational agents
    3. Pigment is light tan to very dark brown
13. Milia
    1. Collection of 1-2mm white, hard, rounded, superficial papules
    2. Usually occur on the face
    3. Lesions contain keratinous contents (can be found by lancing)
14. Senile Angioma
    1. Also called "cherry red spot"
    2. Usually occurs in persons age 20-30
    3. Found on lip or trunk
    4. Usually 2-3 mm bright red, globular papules
15. Senile Lentigo ("liver spots")
    1. Single or group of well circumscribed macules
    2. Usually light yellowish brown due to increase in melanocyte numbers
    3. May gradually develop, over many years, into melanoma
    4. Therefore, lentigos which change in shape or color should be evaluated
16. Spider Nevus
    1. Central, punctate, bright red macule or papule
    2. Fine red lines radiate out (similar to spider legs)
    3. On compression, central body pulsates (blanches)
    4. Most commonly found in patients with portal hypertension (usually cirrhosis)
17. Dermatofibroma
    1. Isolated, slightly elevated, hard, button-like nodules
    2. Usually discolored and <1cm in diameter
    3. Lateral compression leads to dimpling or depression of dermatofibroma
    4. May be confused with melanoma (lateral compression raises melanoma)
18. Skin Ulcers
    1. Pressure ulcers
    2. Lower extremity - common in diabetes mellitus
    3. Venous stasis - particularly in patients with congestive heart failure
19. Keloids and Hypertrophic Scars [4]
    1. Very common abnormalities in wound healing
    2. Due to excess accumulation of collagen in scar
    3. Fibroblasts do not regulate collagen synthesis properly
    4. Fibroblast proliferation is abnormally increased
    5. Increased levels of and/or responses to IGF-1, TGFß, and IL-1 have been noted
    6. Fetal wounds heal rapidly without scarring and express little or no TGFß
    7. Therefore, TGFß is believed to play a central role in scar formation

1. Characteristics
   1. Intense burning pain, increased cutaneous temperature of skin
   2. Intesne, diffuse, erythema of skin, usually lower extremities, no arterial compromise
   3. Precipitation of symptoms by heat and gravity
   4. Relief of symptoms by cooling and elevation
   5. Very uncommon disease
2. Associated Diseases
   1. Myeloproliferative disease with thrombocytosis
   2. Rheumatologic: systemic lupus, rheumatoid arthritis, vasculitis
   3. Pregnancy
   4. Idiopathic
3. Treatment - single dose of aspirin 500mg

H. Ichthyosis

1. Dry, scaly skin
2. Hereditary and acquired forms
3. May be paraneoplastic (usually acquired type)
4. Very uncommon disease

I. Sweet's Syndrome [5]

1. Acute febrile neutrophilic dermatosis
2. Associated Conditions
   1. Malignancy - acute myelocytic leukemia (AML) most common
   2. Infection - Yersinia, Chlamydia, Mycoplasma, Toxoplasma
   3. Drug reaction
   4. Neutrophil overproduction - as with granulocyte stimulating factor (G-CSF, Neopogen®)
   5. Autoimmune disease
3. Symptoms
   1. Erythematous rash - well demarkated papules and plaques, dense white cell infiltrates
   2. Sudden onset fever
   3. Neutrophilia
   4. Endomyocarditis including valve insufficiency and cardiomyopathy can occur
4. Diagnosis
   1. Neutrophilia
   2. Rash with neutrophilic infiltrates
   3. Fever must be present
   4. Cardiac assessmentwith echocardiograqphy and/or endomyocardial biopsy
5. Treatment
   1. Antibiotics - to cover above organisms; doxycycline 100mg po bid
   2. Glucocorticoids - prednisone 40mg qd or equivalent
   3. Continue treatment for ~14 days or until symptoms fade
   4. Glucocorticoid taper as required

References

1. Meisel JL and Mark EJ. 1995. NEJM. 333(25):1695 (Case Record)
2. Fluorouracil. 1993. Med Let. 35(907):97
3. Chren MM and Landefeld S. 1994. JAMA. 272(24):1922
4. Singer AJ and Clark RAF. 1999. NEJM. 341(10):738
5. Dorenkamp M, Weikert U, Meyer R, et al. 2003. Lancet. 362(9393):1374 (Case Report)
6. Schwartz RA. 2004. Lancet. 364(9440):1173