Patient case (clinical description): A 27-year-old woman comes to the dermatology clinic with skin rash and oral ulcers.  The rashes are mildly itchy. The patient has no other medical conditions and takes no medications.  Vital signs are normal.  On examination, there are pink papules symmetrically distributed over the anterior surfaces of the shins and ankles. There are some white ulcerated papules on her buccal mucosa. She is in relationship with her boyfriend and has only one sexual partner. Her boyfriend uses condoms. She smokes 1 to 2 cigarettes a day and drinks a beer daily. Biopsy reveals prominent hyperkeratosis with a thickened granular layer.  There is an infiltration of mononuclear cells in the superficial dermis that involves the overlying epidermis. The rete ridges have a sawtooth appearance.

Patient's own account: I went to the dermatologist because I had rashes on my skin and ulcers in my mouth. The rashes were not that itchy. I don't get it! I'm 27, I don't take medication, nor I don't have any other illnesses. My vitals were normal. My doc told me there were pink spots on the back of my throat. I'm heterosexual and have been only with my boyfriend and he uses condoms. I smoke 1 or 2 cigarettes a day and I drink a beer to accompany it. I had a biopsy and it showed some thick and grainy skin texture. The doc said it's an immune reaction.

Clinical trial: Cigarette Smoking and Oral Microbiota

Eligibility criteria:
-  INCLUSION CRITERIA

        This study will recruit a convenience sample of 50 volunteers (25 current smokers with at
        least 5 years of smoking history, 25 never smokers). Current smokers are defined as
        individuals who have smoked more than 100 cigarettes in their lifetime and have smoked 5 or
        more cigarettes in the last 24 hours. Recent use of other tobacco products (pipe, cigar,
        snuff, cigarillos, and chewing tobacco) is an overall exclusion, but use in the remote past
        (> 6 month ago) is acceptable in smokers. Never smokers are defined as individuals who have
        never smoked cigarettes nor used any other tobacco products including pipe, cigar, snuff,
        cigarillos, or chewing tobacco.

        The ethnic mix of the clinic is roughly 50% Caucasians and 50% African- Americans with a
        small number of unspecified or other racial groups. The median age is about 50 and the
        gender mix consists of an equal number of men and women. We therefore will select smokers
        and frequency match to non-smokers based on ethnicity (White, African-American), gender
        (male, female), and age (above or below the median, estimated to be 50).

        EXCLUSION CRITERIA

        We will exclude pregnant women and other racial groups because they may represent very
        small numbers and thus be difficult to match. Hormonal changes associated with pregnancy
        and unique cultural habits associated with specific ethnic groups could be associated with
        highly unique or variable microbiome patterns, and therefore reduce the power to detect
        differences associated with smoking which is our primary goal. We will also exclude
        subjects with antibiotic usage in the last three months and subjects with previous
        diagnosed major periodontal disease or cancer because they might be potential confounders.
No condition on gender to be admitted to the trial.
Accepts Healthy Volunteers
Subject must be at least 25 Years old.
Subject must be at most 80 Years

Eligibility (NLI label): Entailment