Group 1, Column 1 Flashcards
Name the diagnosis.
- What is the most common associated malignancy?
- This is histologically identical to what three other things?
- How do you treat this?

Acanthosis nigricans
- Most common underlying malignancy is GI adenocarcinoma, especially with palmar involvement
- Derm path buzzword: epidermal papillomatosis
- Histologically identical to CARP, acrokeratosis verruciformis of Hopf and SK
- Can be treated with topical retinoids and AmLactin
What are the four components of acne vulgaris?
- Abnormal follicular keratinization
- Sebum overproduction
- Propionibacterium acnes overgrowth
- Inflammation
Topical retinoids downregulate which receptor?
TLR-2
P. acnes activates this on macrophages, causing inflammation and attracting neutrophils
Describe key findings of actinic keratosis (AK).
- What kind of genetic damage/mutation has occurred?
- UVB causes AKs by inducing thymidine dimers and causing p53 mutations, impairing apoptosis
- Look for “flag sign” with overlying parakeratosis (looks pink) alternating with orthohyperkeratosis (looks blue)
- Rate of transformation to SCC: less than 0.1%

What kinds of immune cells target the hair follicles in alopecia areata and where?
What type of cytokines are involved?
CD8+ T-cells attack bulb, involving type 1 cytokines (IL-2, IL-12, IFN-gamma and TNF-alpha)
What is important to know about the prognosis of ophiasis pattern alopecia areata?

There is a poor prognosis.
What is the opposite of ophiasis pattern?
Sisapho pattern
(This is basically ophiasis spelled backward.)

What are the nail findings in alopecia areata?
- Regular (geometric) nail pitting
- Trachyonychia (or 20-nail dystrophy), where nails are sandpaper-like
What findings on dermoscopy are classically seen with alopecia areata?
- Exclamation point hairs
- Perifollicular yellow dots

What are other disease associations with alopecia areata?
- Atopy (a poor prognostic factor)
- Autoimmune thyroid
- Vitiligo
- SLE
- IBD
What are classic histology findings in alopecia areata?
- What kind of inflammatory pattern is seen?
- What kind of hairs are present?
- Peribulbar lymphocytic infiltrate (“swarm of bees”)
- Catagen-telogen shift
- Increased miniaturized hairs (i.e., nanogen hairs)

What does anagen mean?
- What proportion of hairs are in this phase?
- How long does this last?
- What medicine recreates this phase?
- Hair growth phase and determines length of hair
- 85% of hairs at any particular time
- Lasts 2-6 years (genetically determined)
- Minoxidil recreates anagen phase
What does catagen mean?
- What happens to the hair in this phase?
- What proportion of hair are in this phase?
- How long does this last?
- Transitional phase after anagen
- The bulb regresses and the inner root sheath (IRS) is lost
- 2% of hairs at any particular time
- Lasts 2-4 weeks
What does telogen mean?
- How long does this last?
- What proportion of hairs are in this phase?
“Telogen is tired and resting.”
- Resting phase
- Lasts 3 months
- 15% of hairs at any particular time
Name the layers of the hair follicle from outer to inner.


What is the gene implicated in atopic dermatitis?
Fillagrin mutations, causing alterations in the epidermal barrier
Where is filaggrin located in the epidermal cell and in what layer of the epidermis?
- What does filaggrin do in the cell?
- In the keratohyalin granules of the stratum granulosum
- Filaggrin binds to intermediate filaments, also known as keratin filaments, causing structural integrity

Is atopic dermatitis Th1 or Th2 mediated?
Th2
- Important in allergies, humoral immunity
- Think IL-4, IL-5, IL-6, IL-10, IL-13
Name the Th1 cytokines.
- IL-2
- IL-12
- IFN-γ (downregulates Th2 pathway)
- TNF-α
Important in cell-mediated immunity, delayed-type hypersensitivity reactions
Think ACD, psoriasis
Name the Th2 cytokines.
- IL-4
- IL-5
- IL-6
- IL-10
- IL-13
Important in allergies, humoral immunity
Think atopic dermatitis
Name the diseases associated with Th1 cytokine profile.
- Allergic contact dermatitis
- Psoriasis
- Tuberculoid leprosy
- Cutaneous leishmaniasis
Name the diseases associated with Th2 cytokine profile.
- Atopic dermatitis
- Lepromatous leprosy
- Disseminated leishmaniasis
- Sezary syndrome
- Parasitic infections
What is the classic histopathology of acute atopic dermatitis?
- What happens in the epidermis?
- What kind of inflammatory pattern and what immune cells are present?
- Prominent spongiosis
- Intraepidermal vesicles/bullae
- Perivascular lymphohistiocytic infiltrate with eosinophils

What is the classic histopathology of chronic atopic dermatitis?
- What happens in the epidermis?
- Psoriasiform acanthosis with little spongiosis

























































