Top 5 Summertime Dermatoses
As the temperatures rise and people begin to venture
outdoors to enjoy all the activities that come with beautifully sunny days,
providers will see an influx of patients presenting with a variety of
dermatoses. Over the last 12 years in practice, this is my empirically derived
top 5 list of what to look for and how to treat it.
- Irritant/Allergic Contact Dermatitis:
As the diagnosis implies, these patients will present with a pruritic eruption
after coming in contact with something that they were either allergic to or
sensitive to. The distribution is usually seen in exposed skin areas on the
arms and legs. Most people will report that they were working in the yard, pulling
weeds, trimming bushes, cleaning with harsh chemicals, fertilizing, or spraying
weed/insect killers. If patients were going without a shirt or wearing a
tank-top or bathing suit top, the rash can also appear on the abdomen or chest;
the back is usually spared. The reason is that people will cut limbs, pull
weeds, cut the grass and then pick up the clippings and hold them against their
body to put in lawn bags/compost areas. The eruptions are erythematous with
evidence of excoriations. Treatment includes topical steroids class 1-3 (5-6
for face) twice daily until clear or no longer than 2 weeks and avoidance of
repeat exposure. This is a self-limited condition and would resolve if we did
nothing, so symptom management is the key.
- Discoid Lupus:
Presents as multiple annular/semi-annular erythematous pruritic plaques
erupting in sun exposed regions, usually within 24 - 48 hours. Patients may
believe they have contracted a fungal infection but the pruritis and rapid
development can eliminate this as a potential diagnosis. Gutatte psoriasis and
nummular eczema can be excluded because they tend to improve with sun exposure.
Biopsies should be taken to confirm the diagnosis and an ANA ordered to rule
out systemic lupus. Treatment once again relies heavily on topical steroids
classes 1-3 and avoiding sun exposure. Sun block and protective clothing should
be used daily.
- Tinea Versicolor:
Fungal infection presenting most commonly after sun exposure. Common
presentations include hypopigmented, annular macules on the exposed areas of the
trunk, upper arms and thighs. The sun has nothing to do with the infection
itself, the affected areas just don't pigment normally and patients will say
they have "sun spots" or look like a leopard. Mild pruritis can be seen, but is
rare. Treatment includes topical antifungal shampoos applied like a lotion to
the exposed areas, allowed to sit for 15 minutes then rinsed. Done correctly every
day for two weeks, most will be clear of the infection but should continue to
use the shampoo in this fashion once or twice a week. Repigmentation can take
several months to occur. In extreme cases, oral ketoconazole can be used.
- Cutaneous Herpes Simplex Type I:
The same virus that causes "cold sores" can result in a cutaneous eruption.
Seen commonly on the back 24 - 28 hours after sun exposure, the patient will
present complaining of an itchy, slightly burning sensation on the affected
area. On examination, there is usually a well demarcated erythematous patch
with multiple small vesicles or scabbed papules. This can be differentiated
from shingles by its limited surface area; spots tend to be small and don't
follow a dermatome. Also itching tends to be reported more than intense pain
and this area tends to break out repeatedly in the same location whereas shingles
is usually one and done. Treatment includes antiviral medication and sun
protective measures. Patients should also be made aware that this is contagious
so sharing of towels and clothes is ill advised.
- Photoallergic Drug Eruption:
Differentiated from a drug allergy by the distribution and sun exposure being
the precipitating factor. Eruptions occur most commonly on the forearms but can
occur in any area of prolonged sun exposure. Unlike drug allergies which cause
an overall erythematous eruption and is associated with an actual allergy to a
medication, this eruption is caused by a metabolite of a medication reacting
with UV radiation. It is important to differentiate because the patients do not
need to change their medication - they need to avoid sun exposure. Topical
steroids can be used to calm flares but UV avoidance is curative.
I hope this list can help narrow down the diagnoses
that you will be seeing soon as temperatures rise and UV exposure increases.