Physician Assistant Exam: Skin or Hair Loss Medical Conditions
For the Physician Assistant Exam (PANCE), you will need to review some very serious and potentially life-threatening stuff: skin conditions where you can lose the outer layer, the epidermis of the skin. Make sure you review desquamating diseases, burns, and a very nonfatal skin condition, alopecia.
Desquamation is the loss or shedding of the outermost layers of the skin. Causes of desquamation include Stevens-Johnson syndrome, toxic epidermal necrolysis (TEN, or Lyell’s syndrome), erythema multiforme, and burns.
You never forget Stevens-Johnson syndrome and toxic epidermal necrolysis once you see them. With both conditions, the epidermis, the outermost layer of the skin, is completely destroyed. Toxic epidermal necrolysis is a more severe disease than Stevens-Johnson syndrome, although they’re both life-threatening. The causes of both conditions are many, including hypersensitivity reactions to medications, rheumatologic conditions, and HIV. Medication use is often a major cause of toxic epidermal necrolysis.
The treatment is, in many ways, similar to burn treatment. It includes aggressive fluid resuscitation, nutrition, and electrolyte replacement. Antibiotic and intravenous steroids may be used. One big medication used in the treatment of toxic epidermal necrolysis is gamma globulin. The goal is to modulate the immune response.
Erythema multiforme is a desquamating disorder with multiple causes, including medications, viruses, and rheumatologic causes. This condition is thought to recur because it may be related to an allergen-mediated immune phenomenon. The minor form of erythema multiforme just consists of macular papular lesions. The major form is desquamation, along with papules. You see involvement of the mucous membranes. There’s a strong association between erythema multiforme and the herpes simplex virus.
How to assess and stage burns
Burns are a very serious skin condition. For the PANCE, you should be aware of the staging of burns — first, second, and third degree. The key to understanding staging is to review the skin layers:
First degree: These burns are very, very superficial. Stick your hand on a hot stove for a split second, and you usually get a local, superficial redness. You may also get a first-degree burn from lying in the sun too long.
Second degree: These burns go a little deeper than first degree burns. Note that a burn that first appears to be a first degree burn can become a second degree burn over time. A person who touched a hot stove may have initially had erythema on the affected area; now you can begin to see blisters, which are a hallmark of a second degree burn.
Third degree: These burns mean the loss of the first two layers of the skin. In addition to skin, vascular structures and nerves can be injured as well.
In addition to knowing the degrees of burns, you need to know how much of the body is burned. Medical professionals often use the rule of nines in second and third degree burns to assess how much of the body is damaged.
Treating burns comprises aggressive hydration, electrolyte replacement, and nutrition. Antibiotics are also needed. When the skin layers are lost, the affected person can lose tons of fluid and electrolytes and be prone to infection. People with major burns (second or third degree) are often treated at a burn center.
When you see someone without any hair or eyebrows, think about alopecia. Alopecia means loss of hair, but like ice cream, it comes in several flavors. Here are the three types, based on location of the hair loss:
Alopecia areata: Hair is on the head but with patches of baldness.
Alopecia totalis: No hair is on the head.
Alopecia universalis: The person has no hair anywhere.
Normal male pattern baldness is referred to as androgenic alopecia.
Experts think alopecia is a type of autoimmune process. Right now, there’s no accepted cure for this condition. Minoxidil (Rogaine) may slow the loss of hair.