3-114
is likely systemic), erythema, fever, lymphadenopathy, jaundice, hives; others also possible.
Using Advanced Tools: Labs: CBC with differential for infection (eosinophils in parasitic infestations), anemia;
Urinalysis for urobilinogen, protein, casts, sugar; Stool specimens for occult blood and/or O&P; KOH to identify
tinea infections; Gram stain and/or culture for cellulitis; CXR: to rule out complications.
Assessment:
Differential Diagnosis
Pruritus With Rash
Xerosis (dry skin is itchy skin!) - dry, flaky, macular lesions over large area.
Atopic dermatitis - affects the popliteal and antecubital fossae; dry, hyperkeratotic, confluent papules.
Psoriasis - scalp, external auditory canals, genitals and superior aspect of the intergluteal cleft; plaques of
dry, hyperkeratotic skin
Drug eruptions - erythematous, generalized, fine rash; history of drug/medication use
Urticaria - edema, erythema, wheal reaction to allergen/irritant; may be generalized
Seborrheic dermatitis - oily, flaking skin; often in the hair
Sunburn - sun exposed areas; erythema and edema, with pain
Contact dermatitis (allergic or irritant) - edema, erythema, pain on areas exposed at work (hands, face, etc.)
Pityriasis rosea - history of viral illness; oval, macules and papules on trunk and extremities
Insect bites - single or multiple erythematous, edematous macules
Scabies - linear burrows with excoriations in finger web spaces, axillae, nipples, umbilicus and genitals
Pediculosis (head, body or pubic lice) - excoriations in appropriate areas; visible lice or nits
Fungal infections - erythematous, hyperkeratotic plaques in moist body areas; KOH positive scrapings
Folliculitis - cellulitis around hair shaft
Lichen simplex chronicus - single or confluent papules with mosaic pattern
Pruritus ani or vulva - often due to unknown causes, or from infections (peri-anal strep), infestations
(pinworms), trauma, contactants, cancer, lichen planus or lichen sclerosis, or psychological factors.
Contagious diseases - fever and rash (usually macular/papular); include viral infections (e.g., adenovirus,
measles, rubella, varicella/chicken pox); bacterial infections (e.g., meningococcal, staphylococcal, streptococ-
cal, and secondary syphilis).
See separate sections on scabies, lice, psoriasis, contact dermatitis, fungal/tinea infections and many of the
infectious cutaneous diseases.
Pruritus Without Rash
Thyroid disease - thinning of the lateral eyebrows, loss of skin pigment.
Uremia/kidney failure - proteinuria, casts on urinalysis (UA)
Obstructive biliary disease - urobilinogen on UA, jaundice, abdominal pain
Diabetes mellitus - sugar on UA, polyphagia, polyuria, polydipsia.
Microcytic anemia
Drug side effects - history of medication use.
Neurologic disorders - such as paroxysmal pruritus in multiple sclerosis
Several cancers - lymphadenopathy in many types, low blood cell lines
Pregnancy
See separate sections on jaundice, hypothyroidism, diabetes, anemia.
Plan:
Treatment
- Treat infectious agents (tinea, parasitic, viral and bacterial) as discussed in their respective sections.
- Treat other rashes (psoriasis, etc.) and systemic diseases (diabetes, etc.) as discussed in their respective
sections. - Treat dry skin with a gentle regimen of less bathing (every other day instead of daily) with warm, not hot
water, for short duration (<5 minutes), and either gentle soap like Dove for Sensitive Skin or a soap
substitute (Cetaphil lotion). Cleanse only the areas needing it, like the face, axillae and anogenital region.
Pat dry gently with a towel, taking care not to rub. Immediately apply an emollient like Moisturel or Eucerin
or Vaseline or Crisco. Aveeno Colloidal Oatmeal bath can help, but be sure to rinse off the residual matter.