Author:
Roger M.Barkin
BruceWebster
Description
- Lesion morphology:
- Macule:
- Localized nonpalpable changes in skin color
- Purpura or petechiae (nonblanching with pressure)
- Maculopapule:
- Slightly elevated lesions with localized changes in skin
- Papule:
- Solid, elevated lesions <5 mm in diameter
- Keratotic (rough-surfaced lesion)
- Nonkeratotic (smooth lesion)
- Palpable purpura (nonblanching with pressure)
- Plaque:
- Solid, elevated lesions >5 mm in diameter
- Often results from a confluence of papules
- Nodule:
- Solid, elevated lesions extending deep into the dermis or SC tissue >5 mm in diameter
- Wheal:
- Circular, irregular lesions varying from red to pale
- Vesicle:
- Clear, fluid-filled lesions <5 mm in diameter
- Bullae:
- Clear, fluid-filled lesions >5 mm in diameter
- Pustules:
- Secondary lesions:
- Scales:
- Thin plates of dried cornified epithelium partially separated from the epidermis
- Lichenification:
- Dried plaques resulting in skin furrowing
- Erosion:
- Moist surface uncovered by rupture of vesicles or bullae
- Excoriation:
- Linear loss of the skin due to trauma
- Ulcer:
- Deep loss of the skin involving the epidermis and a variable amount of the dermis and SC tissue
- Configuration:
- Circles or arcs
- Serpiginous (creeping or worm like)
- Iris grouping (bull's eye appearance)
- Irregular grouping
- Zosteriform grouping
- Linear grouping
- Retiform grouping
- Color of a lesion or the entire skin may be due to a number of substances:
- Red or red-brown lesions result from oxyhemoglobin found in RBCs
- The macular erythematous lesions seen in viral exanthema usually represent dilated superficial cutaneous vessels
- Purpura and petechiae result from leakage of RBCs out of the vascular space
- Hypopigmentation or hyperpigmentation represent postinflammatory change from either increases or decreases in melanin production
- Depigmentation refers to the total loss of pigment secondary to autoimmune effect (vitiligo) or congenital disorders (albinism)
- Consistency
- Feel of lesion may be helpful
- Scales represent a proliferative disorder of epidermal cell turnover
Etiology
- Papulosquamous:
- Infections:
- Viral or bacterial
- Rickettsial or fungal
- Allergic reactions
- Autoimmune disorders
- Purpura and petechiae:
- Clotting or platelet disorder
- Vascular fragility disease
- Vasculitis
- Overwhelming infection
- Vesiculobullous:
- Infection
- Drug reaction
- Autoimmune disorder
- Ulcer:
- Infection
- Vascular insufficiency
Signs and Symptoms
- Fever (consider infectious exanthemas)
- Pruritus
- Joint pain
- Abdominal pain
- Heart murmur
History
Obtain a detailed history:
- Age group: Conditions, distribution, and appearance may vary with age
- Development, progression, pattern, and duration of the rash
- Lesions synchronous or asynchronous
- Associated symptoms
- Prodromes - cough, rhinorrhea, pharyngitis, fever, meningismal symptoms, pruritus
- Family history, exposures, immunizations
- Others with similar rash
- Recent travel; insect or arthropod bites
- Medications especially new medications:
- Recent treatments and response
- Generic dermatoses
- Atopic dermatitis; psoriasis
Physical Exam
- Dermatologic description
- Cardiac:
- Pulmonary:
- Abdominal:
- Tenderness
- Hepatosplenomegaly
- Skin: See Essential Workup
Essential Workup
Classify the rash based on the primary lesions:
- Papulosquamous
- Vesicobullous
- Purpuric
Diagnostic Tests & Interpretation
Lab
- Consider, if the rash is purpuric:
- Indicated if fever present:
- CBC
- Electrolytes, BUN, creatinine to evaluate dehydration and scarlatiniform rash (exclude glomerulonephritis)
- Viral culture and titers for suspected exanthems
- Lactate and blood cultures for suspected sepsis/bacteremia
- Lumbar puncture if meningococcus or other meningitides or encephalitis suspected
Imaging
Chest radiograph for suspected pulmonary involvement
Diagnostic Procedures/Surgery
- Potassium hydroxide (KOH) preparations:
- Indicated with scaling lesions to differentiate dermatophytosis from nummular eczema and pityriasis rosea
- Superficial scale sample from active border of lesion removed from the skin with a scalpel or the edge of a glass slide
- Place on a slide and add 1 drop of 10% KOH
- Place a coverslip and gently heat with lighter for 2-3 s slowly without boiling. Allow to set for a few minutes and scan for hyphae
- Wood lamp (UV light):
- Useful in dermatophytosis and erythrasma
- Scabies preparations:
- Most of the mite population resides on the hand s and feet
- Place a drop of mineral oil on the lesion. Scrape with a no. 15 blade to produce speck of blood
- Examine under low power for the mite, ova, larva, or fecal matter
- Dermoscopy. Requires training to utilize
Differential Diagnosis
- Solid, skin colored, or yellow:
- Keratotic
- Wart
- Corn or callus
- Nonkeratotic
- Molluscum contagiosum
- Sebaceous cyst
- Basal and squamous cell carcinoma
- Nevi
- Solid, brown:
- Cafe au lait patch
- Nevi
- Freckle
- Melanoma
- Photoallergic/phototoxic drug eruption
- Tinea nigra palmaris hypopigmentation
- Solid, red, nonscaling:
- Nonpurpuric
- Exanthems
- Rubeola, rubella, or roseola
- Scarlet fever
- Toxin-producing staphylococcal or streptococcal disease
- Erythema infectiosum (“fifth disease”)
- Rubella-like rash (echoviruses, Coxsackie A viruses)
- Varicella (early manifestations)
- Variola (smallpox: Early manifestations)
- Epstein-Barr virus
- Enterovirus or adenovirus
- Mycoplasma
- Kawasaki disease
- Erythema multiforme
- Localized, pruriginous
- Insect bites, scabies
- Allergic or irritant contact dermatitis
- Purpuric
- Bacteremia sepsis
- Meningococcemia, pneumococcemia, gonococcemia, Haemophilus influenzae
- Endocarditis
- Plague
- DIC
- Rocky Mountain spotted fever (RMSF)
- Henoch-Schönlein purpura
- Idiopathic thrombocytopenic purpura
- Leukemia
- Underlying bleeding disorder
- Ecthyma gangrenosum
- Rarely, pityriasis rosea
- Solid, red, scaling:
- Without epithelial disruption:
- Tinea corporis, capitis, pedis, or cruris
- Pityriasis rosea
- Secondary syphilis
- Lupus erythematosus
- With epithelial disruption:
- Papular urticaria
- Eczema
- Seborrheic, diaper, contact, or stasis dermatitis
- Impetigo
- Cand idiasis
- Tinea corporis, capitis, pedis, or cruris
- Vesiculobullous rash
- Herpes virus: Varicella, variola (smallpox)
- Herpes simplex/zoster
- Hand -foot-and -mouth syndrome
- Scabies
- Drug hypersensitivity, toxic epidermal necrolysis
- Staphylococcal scalded skin syndrome
- Impetigo, bullous impetigo
- Catscratch disease
- Dermatitis herpetiformis
- Eczema
- Erythema multiforme
- Lichen planus
Pustular
- Acne
- Folliculitis
- Cand idiasis
- Gonococcemia
- Meningococcemia
- Fever present, consider:
Prehospital
Field management is indicated when there are signs of systemic instability:
- Airway management using precautions to avoid exposure to respiratory secretions; IV access
- Identify rashes with a potentially life-threatening illness or need for special isolation
Initial Stabilization/Therapy
- Aggressive, empiric management of children with a purpuric rash associated with fever or unstable vital signs:
- Airway support, IV access, fluid resuscitation, pressors if cardiovascular collapse
- IV antibiotics should be administered for suspected etiologies
ED Treatment/Procedures
- Specific ED treatment should be directed to the underlying etiology
- Diphenhydramine should be used when an allergic reaction is suspected
Medication
- Acetaminophen: 10-15 mg/kg PO/PR q4-6h; do not exceed 5 doses/24 hr or 4 g/24 hr
- Cefotaxime: 50 mg/kg IV q6h; max dose, 12 g/24 hr
- Ceftriaxone: 50 mg/kg IV q12h; max dose, 4 g/24 hr
- Diphenhydramine: 1.25 mg/kg PO/IM/IV q6h
Disposition
Admission Criteria
- Hospital admission is determined by the underlying disorder
- Other illnesses associated with systemic illness or potential deterioration, SSS, rubeola, and varicella, as well as others, may require inpatient care
Discharge Criteria
Discharge instructions should be based on the underlying disorder
Issues for Referral
- Exanthems associated with self-limited entities in stable children
- Follow-up with primary care physician or dermatologist should be arranged
Follow-up Recommendations
Patient should return for re-evaluation for any rapidly spreading rash, changes in rash morphology, petechiae or hemorrhage, new-onset fever, or neck stiffness
- ChevroletI, HooronsJ, JanssensA, et al. A short dermoscopy training increase diagnostic performance in both experienced and inexperienced dermatologists . Australas J. 2015:56:52-55.
- Dermatology atlas : http://www.dermatlas.org/
- ElyJW, Seabury StoneM. The generalized rash: Part I and part II . Am Fam Physician. 2010;81:726-739.
- Fölster-HolstR, KrethHW. Viral exanthems in childhood. Part 1-part 3 . J Dtsch Dermatol Ges. 2009;7:309-316, 414-418, 506-510.
- O'ConnorNR, McLaughlinMR, HamP. Newborn skin: Part I. Common rashes . Am Fam Physician. 2008;77:47-52.
- RimoinL, AltieriL, CraftN, et al. Training pattern recognition of skin lesion morphology, configuration, and distribution . J Amer Acad Derm. 2015:72:489-495.
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